Satellite signal acquisition is indispensable for signal tracking and solution, and its operating time directly determines the starting speed of the software receiver. The length of Beidou code is twice of Global Positioning System (GPS) C/A code. Therefore, the acquisition time will increase with the traditional algorithm. This paper proposed a fast acquisition algorithm which decomposed the N points Fast Fourier Transform (FFT) to three parts. The algorithm transformed the structure of parallel code phase acquisition algorithm and decomposed the mixed signal and local code into three parts to do FFT operations, and then the correlation results were got by fusion algorithm. In this way, the algorithm did one correlation operation every 3 sampling points and its structure was more flexible. As a result, the amount of calculation was reduced by about 27% and consumption of memory by about 30%. On the other hand, the PTP values of the two algorithms under discussion were very close, indicating their acquisition performances were basically equivalent. In other words, the proposed algorithm can reduce operational time and resource consumption without loss of acquisition accuracy.