To deal with the problem that the stable/unstable manifolds of Earth-Moon Lagrange L1 point can not come close to earth,this paper first introduces the trajectory design method based on disturbance manifolds.The parameterized form of disturbance manifolds is constructed,and by searching through four dimensional parameter space,many numerically optimized transfer trajectories are obtained.Then based on the simulation data,a technique of using angular momentum to explain the transfer mechanism is proposed,which suggests that the design of L1-Earth transfer trajectory should aim at reducing angular momentum,and reveals the dynamics behind the transfer trajectories.Finally,an optimized L1-Earth low energy transfer trajectory is presented,that verifies the efficiency of this method.