To attenuate the effect of unknown disturbances and parameter perturbations, a novel adaptive L₂-gain robust control strategy for the shunt hybrid active power filter (SHAPF) system is proposed. Firstly, an Euler-Lagrange (EL) system model with the disturbance and the parameter perturbation is built for the SHAPF, and the error system of the SHAPF in the dq reference frame is obtained. Then an adaptive control law is presented to estimate the parameter perturbation by using a designed Lyapunov function. Moreover, according to the damping injection method, an L₂-gain robust controller is synthesized which ensures the dissipation in the disturbance attenuation level gamma. Finally, simulation results verify the correctness and effectiveness of the proposed strategy.