The structure of the JD4200 (USA) hydraulic turnover mechanism was analyzed． The technique of inverse seeking design method and optimal design method were used to study the turnover mechanism. Key points were mastered and major parameters were programmed in mathematical model. Computer program was assembled to solve the complicated problem and results were used in the designing of 1LF-335 reversible plow equipped with domestic tractors. The performance of the plows, manufactured by Baoding Plow Plant, was excellent and all the turnover mechanisms were reliable.