The invention discloses a structural parameter optimization method for a six-degree-of-freedom parallel platform. The structural parameter optimization method comprises the steps that firstly, the working space and the dexterity of the parallel platform are analyzed on the basis of a multi-target-multi-constraint algorithm; secondly, the constraint conditions for platform parameter optimization are analyzed by taking the working space size index and the dexterity index of the parallel platform as targets; and lastly, the process of the parameter optimization method is designed on the basis of a Monte Carlo method, and the optimal structural parameters, integrating the working space size with the dexterity, of the six-degree-of-freedom parallel platform are obtained. According to the method, the working space size and the dexterity of the six-degree-of-freedom parallel platform can be simply and intuitively described; the constraint conditions of the six-degree-of-freedom parallel platform in the structural parameter selection and optimization process are determined, the multi-target-multi-constraint algorithm for parameter optimization of the six-degree-of-freedom parallel platform is proposed, and structural parameter optimization can be conducted; the process of conducting structural parameter optimization through the Monte Carlo method is given, and the optimal structural parameters, integrating the working space with the dexterity, of the six-degree-of-freedom parallel platform can be obtained.