Abstract: Quantization is an important part of analog-to-digital conversion in satellite signal reception. Signal quantization brings energy loss, which affects the subsequent signal processing. It can effectively improve this loss on choosing appropriate quantization bits and system reference power according to signal characteristics. The quantization loss is visually expressed in the form of signal-to-noise ratio comparison, and a general analysis formula is introduced. The function of automatic gain control (AGC) module in signal quantization is explained. Combined with quantization loss formula, a selection method of reference power is explained by determining the best gain coefficient, which makes the quantization loss of signals with different signal-to-noise ratios obviously reduced. Simulation results show that this method can improve the quantization loss of satellite navigation signals by about 1.5 dB when quantizing low bits. It has certain reference significance for the design and engineering implementation of the receiver.