Dynamic analysis for the one-DOF parallel mechanism（PM）vibrating screen with one-translation and two-rotation (1T2R) developed by the authors was performed. Firstly, since the PM contained two sub-kinematic chains (SKC) and its coupling degree was 0, it was easy to solve the symbolic solutions of the forward position and directly obtain the (angular) velocity and (angular) acceleration of all links. Then, the ordered single-open-chain(SOC) method based on the Newton-Euler principle proposed by the author’s team was used in the dynamic modeling of this spatial PM with two SKCs, and the driving torque M curve of the actuated joint of the PM was calculated. Comparing the curves obtained by Matlab programming and ADAMS simulation, the correctness of the ordered SOC method based on the principle of Newton-Euler was verified. In addition, the dynamic modeling error analysis was carried out with the driving torque M obtained by the traditional Lagrange method. The results showed that the absolute error range of the ordered SOC method based on the Newton-Euler principle was 33.39% smaller than the absolute error range based on the Lagrange modeling method. It was showed that the ordered SOC method based on the Newton-Euler principle had higher dynamic modeling accuracy. The research result provided a theoretical basis for efficient and precise dynamic modeling of multi-loop spatial PM as well as the motor optimization, parameters optimization and dynamic optimization of the parallel vibrating screen.