Abstract: The RTM filling process of a wind turbine blade was simulated in 3D using the RTM simulation systemto optimize it s RTM process. The simulation result s of two different injection ways are compared and analyzed tofind the optimal injection means. As a result , line injection on the side of the blade is the better way. 8 simulationsare carried out for different injection locations on the side to find the optimal injection location and reasonable outletlocations are ensured. Finally , The optimal process is applied successfully to manufacture the blade. Using the system of RTM simulation to optimize the process is cost-effective and the optimal process for blade manufacture is ofgreat reference value for other shape-similar component s.