To establish the uniform situation map, the platforms’ low-precision navigation information and the location information measured mutually are used to carry out the sensor data alignment for martime multi-platforms. This method can avoid the dependences on high-precision navigation equipments and the errors introduced by assuming the earth’s surface to be the plane. The models of coordinate conversion for aligning are presented. Then the measure equations and the state equations with regard to navigation systematic error and sensor systematic error are built respectively, and a registration algorithm based on Unscented Kalman filtering is designed for estimating online and compensating those two systematic errors. Consequently, the error registration for martime multi-platforms is achieved, and the higher precision information can be provided for the subsequent data association and data fusion. The simulation results demonstrate the correctness and validity of the algorithm.