1. Use Shrinkage Agent: There are special sweater shrinkage agents on the market, which can reduce the mesh of fabrics. Try it before using it.

2. Hand ironing: High temperature ironing will shrink the length of the fabric. The intensity and temperature should be carefully controlled to avoid distorting or damaging the pattern.

3. Treatment with hot water: soak the cuffs or neckline of the sweater in boiling water for a few minutes, and then stretch the required length to keep the shape cool.

4. Re-sew the suture line: re-thread the cuffs and neckline, and tighten the thread to tighten the fabric. Need sewing equipment and thread of the same color.

5. Use a rubber band: wrap a rubber band around the cuff or neckline, and then fix the sweater on the model for a period of time to keep it in shape.

6. Ironing molding: firstly, break the cuff or neckline into a suitable length, and then iron it at high temperature to keep the new shape.

7. Make it worse: redesign the style of cuffs and neckline, and turn over the lattice of some fabrics to achieve the effect of shrinkage.

The above methods can be used in combination. Repairing is troublesome, and chemical shrinkage agent, thread tightening and re-ironing are relatively simple and efficient.