Abstract:To reasonably and dynamically predict the extreme stress information of inservice bridge, in this paper, the nonlinear dynamic models were built including monitoring equation and state equation with the longterm everyday monitored extreme stress data of bridge health monitoring (BHM) system. Then the improved Gaussian mixed particle filter (IGMPF) prediction algorithm was introduced which was obtained by using extended Kalman filter (EKF) and GMPF. IGMPF can predict onestep forward prediction distribution parameters of monitored extreme stress and the posteriori distribution parameters of extreme stress state variable. Finally, an actual example was provided to illustrate the application and feasibility of the IGMPF algorithm built. The IGMPF prediction algorithm can not only obtain the reasonable importance functions of monitored extreme stress states, but also solve the problems of shortterm prediction and low precision of the traditional prediction methods. It provides a theoretical foundation for dynamic response prediction of the actual BHM.