Abstract: A two DOF planar parallel robot mechanism with two coaxial actuators is designed in this paper, whose structure is more concise than the traditional 5R mechanism.Firstly, the forward and inverse kinematics equations are established according to the position relationship of the mechanism, and the Jacobian matrix expression is obtained.Secondly, on the basis of kinematics, some operational performance indexes of the mechanism are analyzed, which includes workspace, singular configuration and Jacobian condition number.The dimension parameters of the components are determined according to the performance goal of isotropy.Finally, the vector expressions of velocity and acceleration of each component are derived, and the dynamic equation of the mechanism is established according to the principle of virtual work.Taking the given trajectory of point P as the target, the laws of driving torquesare calculated.The results show that the robot has good motion performance and high acceleration performance, which provides a theoretical basis for the popularization and application of the mechanism