The invention discloses a non-linear spring suspension active control method based on passivity. Active control research is conducted on a suspension system described by 1/4 vehicle models on the basis that the spring non-linear rigidness characteristic of the suspension is considered. By analyzing the characteristics of a non-linear spring suspension system mathematical model and selecting an appropriate expected internet matrix, damping the matrix and an energy function, a non-linear spring suspension active controller is obtained based on a passivity control theory, the active controller is suitable for bad terrain conditions, can effectively reduce the acceleration amplitude of a vehicle body and the control quantity amplitude, has a more rapid convergence speed, and the vibration decibel of the acceleration of the vehicle body is also obviously reduced in a human sensitive area with the frequency being 4-8 hertz.