Wind turbine transmission chain is the key component of wind turbine to bear various loads, and its working characteristics are an important basis for testing the stability, reliability and safety of wind turbine. Aiming at the transmission chain system, a load simulation technology for ground test system of 1.5MW wind turbine transmission chain was proposed. According to its performance and requirements, a hydraulic loading system with 6-dOF load was designed. Hydraulic loading system is designed according to wind load. Through the mechanism method to establish its mathematical model, particle swarm optimization algorithm is easy to fall into the local optimal solution, using quantum particle swarm optimization algorithm, through Matlab/Simulink load simulation of the hydraulic loading system, the results show that the hydraulic loading system has a good tracking and reproduction of wind load