Abstract: In the multi response optimization design of 3-RRR compliant parallel micromanipulation platform, there are various factors and interaction effects, which make the influence degree of each variable combination on the objective function difficult to control. From the statistical point of view, a variable optimization design method is introduced to improve the robustness of the mechanism. Firstly, the motion model of micro positioning platform is established, and the experimental design is carried out on the basis of the model, and the data are tested by KMO and Bartlett spherical tests. After the analysis, some variables with small weight are disposed of, and the result is that factor analysis can be carried out to score all combinations, so as to find out a feasible variable optimization design scheme. The example conclusion shows that the factor analysis method introduced from the statistical point of view can provide a new solution for the multi-objective robust parameter optimization design of micro mechanism.