An adaptive data fusion algorithm for a multi-rate sensor system based on incomplete measurement is proposed.The algorithm builts a method of sensor subsystem fault detection.The subsystem failure is detected and the incomplete measurement is confirmed to avoid contaminating the entire system by single failure.The subsystem switch control logic is built

mapping matrices are introduced by the algorithm

and new information sharing coefficients are defined.The algorithm can adaptively select subsystems for the center integration.When the incomplete measurement information of the subsystem is found

the predictive value displaces the state estimation for the fusion.The current time estimation value and a priori value of the subsystem are used by the global state estimation

and the fusion performance is improved.The simulation result verifies the effectiveness of the proposed algorithm.