A midsole molding method includes the following steps: creating an upper surface model of a midsole based on a personalized foot information and a human factor information; installing or forming the upper surface model on a bottom of the production mold; and placing the upper surface model inside a sole mold, to form the midsole between the upper surface model and the sole mold. Through the above molding method, the midsole can have ergonomic designs to have the support of insoles, to rectify the gait, or to relieve partial pressure etc. The disclosure can offer a foot-improving effect without the need to place insoles inside the shoe.