Floating thumb is a relatively rare hand and foot deformity, the most obvious feature is that the thumb is missing the metacarpal bone, the thumb is weak and sagging in the shape of floating, can not make force, lose the function of the thumb, some larger floating thumb baby will also appear to pinch the phenomenon of objects. Once you find that your child has the above symptoms, you must seek medical attention in a timely manner, and the sooner you do the surgery to correct the floating thumb, the better. Nowadays, our treatment for floating thumb mainly adopts the hemipalmar bone grafting and reconstruction technique to preserve the five fingers, taking part of the bone from the first metacarpal of the affected hand to reconstruct the first metacarpal, which can greatly reduce the chances of bone aspiration and necrosis. The entire operation is performed on the hand only, without causing trauma to other parts of the body, and post-operative care is simple. The hemi-metacarpal bone graft reconstruction technique can be operated when the child is about 6 months to 1 year old, which coincides with the stage of the child’s thumb function development. At this time of surgery, the child is less likely to develop the habit of pinching objects and the establishment of thumb function will be smoother. The surgery is divided into two phases. The first phase is to move the bones so that the thumb has a good shape, and then after he has grown well, the second phase can be done to rebuild the function of the thumb so that it can move. After the two-stage surgery, parents need to guide their child to do functional exercises and slowly try to use the thumb to make him realize that he can move his thumb, and he will be more and more willing to use his thumb. Parents can give the child some interesting toys to play with while guiding the child to do functional exercises, so that the child will not be resistant to functional exercises. As long as all aspects of the child’s thumb work well together, the child’s thumb can reach an ideal state of form and function, writing, drawing, screwing bottle caps, etc.