A bidirectional moving platform driven in parallel was designed. The platform was driven by a slider fixed on a verticallymoving linear moving component on the base. The slider was connected to the slot bracket, and the four sides of the rectangular platform were supported by the slot type. The moving pair was used to guide each other, by which the movement in two directions could be realized at the same time. Based on the virtual work principle and Lagrange method, the dynamic equation of the platform was established. The dynamics simulation analysis was carried out. Given the torque required by the motor to achieve the specified motion under the external load, the feasibility of the platform motion and the correctness of the dynamic model are verified. According to the error independent action principle, different types of error sources were analyzed and calculated to get each local error. The local errors were integrated according to the principle of error synthesis, and the motion error limits in the two directions X and Y of the table were obtained.