One parent said that their child was born with a right thumb deformity, and when they went to the local hospital, the doctor said that there was no way to preserve the five fingers, and that they could only do an index thumb. There are many treatment options for floating thumb, but thumb thumbing is the more traditional one. If we do thumb thumbing, the child will only have four fingers left after surgery. In fact, the floating thumb can be preserved through surgery. Previously, we used the metatarsal reconstruction option, but now we are using the hemi-metacarpal bone graft reconstruction option. The first stage is to reconstruct the metacarpal bone and the second stage is to reconstruct the function of the thumb. Functional exercises after floating thumb surgery are very important, we will instruct parents how to do functional exercises, parents should encourage, help and ask their children to do functional exercises such as grasping, gripping and pinching after they are clear, no matter if it is mom or dad with their own children, or grandparents or grandparents with their children, they should pay attention to functional exercises. Through functional exercises, the child can grip relatively large objects, and can also hold some small objects, writing, holding chopsticks, holding spoons, pinching green beans, pinching rice grains and other actions can generally be done. The time of surgery for hemi-metacarpal bone graft reconstruction should not be too early, if it is too early, the child’s metacarpal bone width will not be suitable, but also not too late, too late is not conducive to the establishment of the child’s thumb function. In general, we recommend that children receive surgery between the ages of 6 months and 1 year, an age when we can perform surgery as long as the child is in good health, his weight is up to standard, and the width of the metacarpal bone is appropriate.