PID control is used widely in hydraulic servo control system. The PID control parameters are very important to performance of hydraulic servo control system and how to find rapidly the optimum values of PID control parameters is very difficult problem. A novel algorithm, called BF-EMPCEOA algorithm, that is combined Bacterial Foraging Algorithm with the elite multi-parent crossover evolutionary optimization algorithm (EMPCEOA) was proposed. Based on Matlab/simulink software and taking the IATE standards of optimization design as objective function, the proposed method was applied for the optimization of the three parameters of PID controller of electric-hydraulic servo system of 6-DOF parallel platform. Simulation results show that the proposed parameter optimum method is an effective tuning strategy and has good performance.