In this article, GPS L1C/A and L2CM code signal combined acquisition technology was studied, the double combined generalized difference acquisition technology was used to solve the problem of data bits jumping due to the cyclic of satellite navigation data, and improve the acquisition sensitivity. Then the multiplicative method was introduced to improve the detection probability and acquisition correlation ratio between the first main peak and the second one, making it is more suitable to achieve acquisition in weak environment. The experimental results show that this acquisition technology improves the sensitivity of 3 dB than single code acquisition technology, at the same time, the improved algorithm when under the condition of the input SNR is 24 dB, existing navigation data jump, it can capture signal successfully, the ratio of the first main peak to the second peak is 5.23, increasing by 4.25 times than the traditional algorithm.