To solve the problem of nonlinear multi-agent cooperative output regulation under topology switching and time delays,a distributed state observer control algorithm and a fuzzy feedback control strategy are proposed.Firstly,the T-S fuzzy model is used to transform the nonlinear system into a linear system.Secondly,for the cooperative output regulation problem that the follower agents cannot obtain the state of the external leader system,a distributed state observer and a fuzzy output feedback controller are designed.The state observer is used to estimate the state information of the external leader system,and the state information is then fed back to the controller of the system,which solve the problem that the followers cannot obtain the state of the external leader.Thirdly,Lyapunov stability theory is applied to prove the stability of the nonlinear multi-agent system under topology switching and time delays.Finally,the correctness and effectiveness of the control law are verified by Matlab calculation examples.The simulation results show that the designed state observer can solve the problem of system state unmeasurability,the followers can track the leader signal,and the tracking error is zero.