Autonomous navigation places an extremely high demand on the acquisition sensitivity of the global navigation satellite system (GNSS) receivers. To increase the efficiency and sensitivity of the acquisition algorithm of GNSS weak signal, we improve the acquisition algorithm named Improved Acquisition Algorithm with Doppler Frequency Compensation (IAADFC) proposed in our previous study. The bottleneck restricting the performance improvement of the IAADFC algorithm is that it is difficult to estimate Doppler frequency and navigation message bit flip estimation in a very weak signal environment. We provide a detailed analysis and comparison among the proposed IAADFC algorithm, non coherent integration (NCI) algorithm. Simulation results demonstrate that our IAADFC acquisition algorithm can effectively realize the acquisition of GNSS signal with a singal-to noise ratio that down to 15 dB•Hz which is the current most advanced level of signal acquisition.