The invention relates to a simulation system and a simulation method for simulating a manufacturing process of a wind turbine blade mold. The system comprises a flow field configuration and a mesh splitting unit for receiving and storing input flow field configuration initial setting parameters. A process parameter setting unit for receiving and storing an input vacuum-assisted resin filling process initial setting parameter; a material property database unit for storing material data in the flow field; a vacuum-assisted resin injection process simulation unit for calculating quality parameters of a wind turbine blade mold; a part quality prediction and defect control unit used for judging whether the flow front, dry spot defect and gas enrichment defect of resin in the flow field conformto the requirements of the initial design of the product according to the calculation parameters, if not, optimizing and adjusting the initial parameters of the flow field configuration, the initial parameters of the vacuum-assisted resin pouring process and the data in the flow field. The system and the method of the invention can obtain the optimized parameters of the mould for producing the wind power blade.