In response to the problem of the denial-of-service (DoS) attacks that the network layer of cyber physical power system (CPPS) is prone to, a DoS attack detection and defense method integrating state estimation and model predictive control (MPC) is proposed. On the sensor side, a multi fading factors adaptive Kalman filter is adopted for state estimate. This algorithm overcomes the drawbacks of the traditional Kalman filter which is prone to divergence and the single fading factor adaptive Kalman filter which has low estimation accuracy, and a residual detection algorithm is designed based on the estimation results to realize attack detection. On the controller side, MPC is introduced, which calculates the control signals for the future period by using the newly received state estimation signals to compensate for the data loss caused by DoS attacks. Meanwhile the predictive control sequence is designed on the basis of Lyapunov stability theory and linear matrix inequalities (LMI), which solves the problem of system instability caused by data loss. Finally, simulation verifications are conducted on the IEEE 9-bus and IEEE 30-bus test systems. The results show that the proposed detection method can detect DoS attacks in a timely manner, and the defense method can effectively maintain the stable operation of CPPS under DoS attacks.