In order to eliminate the inconsistency of the existing data from multi-satellite missions, we propose a new method for optimal combination of altimeter data. In our data management system, the crossover adjustment is modified to two-step processing based on the a posteriori compensation theory of error; i.e., the crossover adjustment of condition equations is made in the first step, and the filtering and prediction of adjustment corrections done along each single pass in the second step. Using the new approach can simplify greatly the computational procedure of crossover adjustment, and the stability and reliability of its solution can be expected. The new method can be used for both local and global crossover adjustment problems. Finally, a practical altimeter dataset from Geosat, ERS-1, ERS-2, and TOPEX/POSEIDON (T/P) is used as a case study to prove the efficiency of the integrated data processing method.