Such a thumb has no metacarpals, no tendons and is floating. From the doctor’s point of view, we recommend preservation. There are two ways to preserve it, one is to take the metatarsal bone and the other is to take the metacarpal bone. There are some problems with taking the metatarsal bone, such as longer surgery time, possible resorption and necrosis of the graft bone, and residual surgical scarring in the foot. Now we use the method of hemi-metacarpal bone graft reconstruction to preserve the floating finger. With this method, the operation time is shortened, the chance of bone resorption and necrosis is reduced, and the child’s foot will not be affected in any way. From our follow-up, the surgical result of hemi-metacarpal bone graft reconstruction is still satisfactory. After the surgery, the child can palm to palm, grasp, pinch and pinch.