In order to optimize the drive system of electric forklift and reduce the cost, a new type of hydrostatic transmission system including hydraulic system and control strategy, was proposed for 3.5T forklift, which combined the characteristics of motor frequency conversion technology, low speed motor drive and open circuit. AMESim software was used to model and simulate the driving system, and the performance of the system was analyzed. The results show that the drive system can realize driving, micro-motion, automatic shift, smooth braking and other functions. The driving speed, gradeability and other properties are in accordance with industry requirements.