Taking the reconfigurable 3-RRR planar parallel mechanism（PPM）as the research object, the kinematic chain constraint is applied to the precision planar 3-RRR flexible PPM to solve the problems of complex driving and control and high energy consumption. The inverse kinematics equation of the reconfigurable 3-RRR PPM is established using the closed vector method to solve the equation. On this basis, the sensitivity function mapping model of the component parameters and output parameters of the reconfigurable parallel mechanism is established with the component parameters as the influencing factor. The sensitivity orthogonal experiment simulation analysis of the functional model of the mechanism is carried out using Matlab, and the numerical simulation results are obtained. The analysis results show that the influence direction and sensitivity direction of the component parameters on the output parameters of the mechanism are consistent, providing an effective reference for the parameter design and motion position accuracy design of the improved planar reconfigurable 3-RRR parallel mechanism.