The invention discloses an SINS/GPS integrated navigation based Kalman filter numerical optimization method. According to the method, on the basis of establishing of an SINS/GPS integrated navigation conventional Kalman filter model, a block matrix technology is used, high-order matrix operations involved in filter calculation is deduced in accordance with sub-blocks in the Matlab environment, and a great number of meaningless duplicate operations are prevented; numerical value decoupling with other updating processes is obtained in the sub-process level through a time-consuming parameter segmentation calculation process, and accordingly, a novel lossless parallel processing mechanism is given, and the filter calculation timeliness is improved greatly. By the aid of the method, the defects of complex deduction and the difficulty in project implementation of common filter decomposition optimization algorithms are overcome, traditional lossy accuracy decoupling in parallel filters is prevented, and efficient lossless data filters of the SINS/GPS integrated navigation system is achieved.