In Global Navigation Satellite System (GNSS) receiver, the prior information of navigation filter can be used to aid signal acquisition in order to increase acquisition speed and improve sensitivity. By taking the BDS B1I signal as the research object, studies on the estimation of pseudo-random code phase, carrier Doppler, and NH code phase aided by navigation filter in GNSS receiver were carried out. First, the concept of “virtual route” was introduced to derive the computing method of pseudo-random code phase by directly using navigation filter. Then, the error sources and propagation characteristics of pseudo-random code phase and Doppler frequency were analyzed thoroughly. Finally, the theoretical simulation analysis of acquisition performance was conducted. Results show that when estimating pseudo-random code phase and Doppler frequency aided by navigation filter, the acquisition sensitivity was improved by 1.1 dB, and the mean acquisition time was 1 ms. By further aiding the estimation of the NH code phase, the coherent time was extended to 20 ms, the additional acquisition sensitivity improvement of 12.8 dB was achieved, and the corresponding mean acquisition time was 20 ms. The performance of signal acquisition could be improved by utilizing the prior information of navigation filter. Meanwhile, the power consumption caused by frequently running of unaided acquisition engine could be decreased. The algorithms proposed in this paper can be directly applied in GNSS receiver or GNSS/INS deep integration system.