Because there are only some basic concepts in junior high school and senior high school, it has always been thought that sketch is a simple pencil drawing, and this idea has even continued to the university. Until I came into contact with the course of sketch color, I had a new understanding of sketch. Sketch is the mother of all plastic arts. Sketch is the basic form of painting art, and it is also a means and teaching effect in basic art teaching. At the same time, excellent sketch works should also be an artistic eternity, which has its own thoughts, the pulse of the times and emotional experience. In the history of Chinese and foreign art, there are many classic sketches of great artists, such as Italian Michelangelo, German Menzel and Russian Lie Bin. China's Xu Beihong, Wang Shikuo and others all have masterpieces handed down from generation to generation. As we all know, it is one of the necessary conditions to have certain sketching skills and techniques, especially for non-art students in lower grades like us. On the other hand, the technique of sketch is not unique, it depends on the author's personal understanding and emotional experience of objective things, and expresses the author's aesthetic views through sketch skills and techniques. As students of design colleges, we should start with traditional sketches and do basic imitation and training first. Therefore, in the beginner stage, we have done a lot of geometric object painting training, hoping to cultivate the traditional sketch ability to accurately describe the relationship between natural form and space through this method. However, design sketch is different from traditional sketch. The purpose is to train designers, mainly to study the internal composition and overall appearance of objective objects, so as to go beyond imitation, achieve active understanding and creation, and organically combine the modeling language of artistic expression with professional design. Therefore, in the learning process, we should emphasize the essence of design and the training of conception and imagination. Our courses and majors pay more attention to architectural composition, so it is particularly important to clarify the perspective relationship in the process of sketching, so we should constantly train and learn the perspective relationship of geometry. But the accuracy of perspective is not the only criterion to measure the beauty of the picture. You can distort, flatten and exaggerate the image of the screen object, change the aesthetic standard of fixed thinking, and improve your artistic thinking and aesthetic ability. Traditional sketch has strict requirements for composition, while design sketch may completely break the balance of the picture, and pursue fullness, danger, space, deviation and locality in composition. In this way, we can gain unexpected freedom in the choice of screen space. Based on the three-dimensional structural modeling of industrial design, common objects can be simplified into geometric shapes, and most of the painted objects are placed in different positions below the line of sight. In order to clearly grasp the structure of the object and accurately grasp the angle and proportion, the horizontal line, vertical line, central axis, diagonal line, tangent line, overlapping and negative part of various structures are drawn, and the method of controlling and retaining structural lines is used as a sign of further deepening, avoiding the use of light and shade, and obtaining a three-dimensional effect through the light and heavy line drawing. In addition, we can also conduct a separate detailed study, and lay the foundation for drawing more complex architectural compositions in the future through the study of basic shapes. Through the course of sketching colors, I try my best to learn how to emphasize the relationship between light and objects, and how to describe brush strokes in constant sketching practice, so as to present the body observed by my eyes concretely and subtly, and cultivate my observation ability and practical ability. I still remember when I first started sketching, the teacher asked me to draw with a piece of paper. I just drew a little in the corner and didn't dare to use my imagination to create. I hope to draw objects more realistically and objectively, but I can't keep up. I have always felt that my paintings are not as beautiful as others, so I dare not show them boldly when composing music. Through some exercises and in-depth understanding of the basic knowledge of composition, I keep trying to draw enlarged pictures, so that I am no longer afraid of practicing and become more. Because sketch is the basis of painting, and it is the kind of painting that can best reflect people's painting level. For the sake of professional study and the future, I must remember to be down-to-earth, persistent and not impetuous in my study. This is what I experienced and realized in the process of sketching colors.