In order to effectively recycle vibration energy of vehicle suspension, the factors concerning the recycling and their relationship are analyzed. First, the dynamics and energy recovery circuit model of a composite electrical-magnetic suspension system(CESS) are constructed. Then, the relationship among the energy input, output and dissipation of suspension system is discussed. The influence of resistance ratio, excitation frequency and amplitude on energy recovery efficient and energy recovery power is analyzed when considering transportation efficiency. Further, the relationship between vibration attenuation and energy recovery performance is discussed, and the influence of circumscribed resistance and suspension relative kinematic velocity on energy recovery performance is analyzed. The results indicate that the proposed method can analyze the flow relationship of suspension energy effectively use the method of power flow; energy recovery efficiency and energy recovery power are influenced by multiple factors like resistance ratio, excitation frequency and amplitude; Suspension system fails to contemporarily reach the maximum energy recovery efficiency and maximum energy recovery power, and the vibration attenuation and energy recovery performance of suspension system constraint each other.