Tools to be prepared for mending a hole in a sweater are relatively large needles, crochets and threads of the same color as the sweater. Put the wool on the needle and adjust the original hole. If the hole is too small, choose a bigger hole and expose the sweater button when knitting. Leaving the broken copper wire outside finally worked. Put the needle with wool on it around the hole line, pull out the wool and leave a piece of wool at the end of the sweater. Because the sweater is knitted line by line, it is also mended line by line, starting from the rightmost button, starting from the first button, wearing it from bottom to top along the direction of the sweater button, pulling out the wool, then passing through the sweater button from the upper direction, pulling out the wool, returning to the lower button, passing through it from top to bottom, and mending the first line after pulling out the thread. Similarly, first pass through the bottom sweater button, take out the wool, then pass through the top sweater button and put it back. Repeat this method until the hole is repaired. After the hole is mended, the hidden thread and the needle are threaded along the grain direction of the sweater. Note that the hidden thread is better to be longer, so it is not easy to fall off. Pull out the thread after it passes through and cut off the excess thread.