Aiming at the problems of low forming efficiency due to many tooling dies in the existing form-ing technology f copper-nickel reducer for marine,which need to be changed many times in production,A split-inlay molding technology was proposed combined with the forming process characteristics of reducer.The DN80/DN65 reducer was analyzed,and designed the split-inlay forming dies,also we verified the pos-sibility of split-inlay method by finite element method,the split-inlay forming die was made to physical verification.The results showed that the forming effect of the split-inlay forming method was good and the reducer product performance was good,and the product qualification rate was increased to 83%.