Aiming at the fault estimation problem of a class of nonlinear systems with disturbance, a new method combining H∞ robust observer with fault estimation filter is designed.Firstly, this method inhibits the influence of unknown disturbance and system noise by introducing H∞ performance index, and inhibits the influence of the rate of fault change on fault estimation error, thus to increase the rapidity and robustness of fault estimation.Secondly, the estimation fault is adjusted by the residual signal after suppression of the H∞ robust observer, and then the threshold value of the filter is designed, and the threshold is compared with the residual norm to determine whether the filter is started or not.The design of the filter further enhances the robustness of the system.Finally, the simulation results verify the validity and correctness of the proposed method.