Compared with traditional threephase inverters, highpower multiphase variable frequency drive system could reduce the voltage by increasing the number of phases under the condition of unchanged power. It could speed flying start in a very short period of time, and operate under grid connection and bypass modes in the absence of under phase loss. The whole system had the advantages of safety and reliability, high system efficiency, low vibration, low noise, low cost, energy saving and environmental protection. The topology structure of starshaped multiphase variable frequency drive system with highlow voltage conversion was described in detail, and the parameters and structure of highpower multiphase variable frequency drive system were designed. Through the test and verification of the engineering prototype, the advantages nature of the product were proved based on data analysis, test results and field operation.