Aiming at the problem of cooling water flow distribution for multi-cavity hot stamping molds, a cool? ing water flow distribution method is proposed. A simulation model of the hot stamping process of U-shaped parts with variable channel parameters is designed. Based on the joint simulation of FLUENT and LS-DYNA, the variation law of the temperature of the formed parts with the thickness of the sheet, the holding time, and the velocity of the pro? file is studied, respectively. And the flow distribution of the mathematical model is established. When the target tem? perature of the part is determined, the specific flow rate required for cooling the thin plate can be quickly determined according to the constructed flow distribution mathematical model, and the reasonable distribution of cooling water in each cavity can be realized. Taking a one-mold three-cavity hot stamping mold as the research object, the valve opening of its external waterway is adjusted according to the established flow distribution mathematical model, and the results before and after the adjustment are compared. After the adjustment, the temperature of the thick plate threshold drops from160.4 ℃ to 150.1 ℃ with a drop of 6.42%. The research results show that the adjustment of the cooling water flow has a significant effect on the final temperature of the formed part. The method of cooling water flow distribution of the multi-cavity hot stamping mold can shorten the overall pressure holding time.