A new concept using flexible tether-net system to capture space debris is presented in this paper.With a mass point assumption the tether-net system dynamic model is established in orbital frame by applying Lagrange Equations.In order to investigate the net in-plane trajectories during after cast, the non-control R-bar and V-bar captures are simulated with ignoring the out-of-plane libration, the effect of in-plane libration on the trajectories of Bilberry the capture net is demonstrated by simulation results.With an effort to damp the in-plane libration, the control scheme based on tether tension is investigated firstly, after that an integrated control scheme is proposed by introduced the thrusters into the system, the nonlinear close-loop dynamics is linearised by Plein air - Accessoires - Sac a dos feedforward strategy, the simulation results show that feedforward controllor is effective for in-plane libration damping and enable the capture net to track an expected trajectory.