The method is as follows:

1. Prepare the needles and yarn, and start with 48 stitches.

2. Start knitting from the bottom of the sweater, start knitting up and down stitches, knit the edge of the sweater, and knit to the desired width.

3. Knit the lower stitch on the front and the upper stitch on the reverse side. At the edge of the front placket, continue knitting 4 stitches on each side and knit up and down stitches on both sides.

4. After knitting 5 rows, close one stitch on the inside of the edge, and continue knitting 5 rows and close one stitch in the same way.

5. Continue knitting 3 rows and knit to the armpit and close one stitch while dividing the front and back pieces. Knit the front at the same time on both sides of the added line, and close the stitches on both sides at the front placket after knitting 3 rows. Repeat the operation twice, and close the stitches until there are 8 stitches on the needles on both sides. Continue knitting 4 stitches on each side of the front placket to the back collar and sew.

6. Knit the back piece, and sew it after it reaches the same width as the shoulder without adding or subtracting.

7. Knit the sleeves, pick up the sleeve loops and make a 16-stitch circle sleeve. When it reaches one-third of the sleeve length, reduce one stitch on the extension line of the armpit, and then reduce one stitch again when it reaches two-thirds.

8. When the sleeve length is enough, knit the upper and lower stitches of the sleeve, knit the sleeve, and use the same method to knit the other sleeve.