For solving the real-time problem of the software correlator, a parallel receiving model of spread spectrum signal based on vector dot product was proposed. The calculation speed of the signal correlation was improved by parallel computing correlation value of each channel with a large number of ALU in GPU(graphics processing unit). Simulation results show that, 25 channels with 150 correlation computation consume 967 μs in all for 1 ms signal of 25 MHz sampling rate by using the vector dot product parallel correlation algorithms based on GPU. Compared with the implementation on CPU based on MKL(math kernel library), the proposed method speeds up to 61.4 times, and the real-time correlation of the broadband spread spectrum signals in software can be realized.