In order to analyze the impact of tether flexibility on the dynamics of CCPTS (Continuous Cislunar Payloads Transfer System) the 2D flexible dynamics of CCPTS is built by using Lagrange method and the numerical simulations are presented. Firstly, the comparison analyses between the 2D flexible model and the 2D rigid model show that the flexibility of the tether affects the orbital elements and attitude elements of CCPTS, and makes these elements of CCPTS out-of-step and increases with increasing time. The chief satellite’s radial acceleration and true anomaly angular acceleration produce some burr due to the flexibility of the tether. The gravity gradient torque caused by the tether affects the CCPTS differently. The angular velocity of tether by the gravity gradient torque regularly varies with time when external torque is zero. However, the angular velocity increases linearly with time while external torque is nonzero and the increasing speed is decided by the magnitude of the external torque. Moreover, the transverse vibration and longitudinal vibration of the tether are affected by the variations of the initial tether angular velocity and tether length.