75000 1。 According to the postcode database, the postcode of xingqing district, Yinchuan is 75000 1. Yinchuan, referred to as "Yin" for short, is the capital of Ningxia Hui Autonomous Region and an important central city in northwest China approved by the State Council. Yinchuan is located in the middle of Ningxia Plain in the upper reaches of the Yellow River.