Abstract: The researches on double mode receivers have become hot points when several constellation systems are completed.The design project of double receiver on GPS/GLONASS is given.GPS/GLONASS signals acquisition is researched in low signal to noise ratio circumstance.GLONASS signals and GPS signals are detected using a FFT-based fast acquisition algorithm and coherent integration with non-coherent integration acquisition algorithm.Finally，signal acquisition algorithm of double receiver is simulated using real signals.It can be seen that GPS/GLONASS double mode receiver is capable of detecting satellite signals in low signal to noise ratio environment，and improves receiver sensitivity.