Abstract: How to achieve precise synchronization is a technical problem that must be addressed in today,s military operations in the highly dynamic conditions. In the conditions, the bit rate offset and carrier frequency offset will affect the precise synchronization accuracy. An improved Pseudo Noise (PN) code phase measurement method based on the least squares method is proposed, and the precise synchronization ability of this method in high-dynamic conditions is proved by theoretical analysis and simulation. The theoretical analysis shows that the method can eliminate the impact of carrier frequency offset and be of strong anti-noise ability. While the numerical simulation manifests that this method is not sensitive to bit rate offset when the length of the selected PN sequence is not very long, and proves that it is of strong anti-frequency offset. The measurement results demonstrate that this method not only achieves a high measurement accuracy, but also possesses good anti-noise and anti-frequency offset ability.