To address the difficulty of fixing full ambiguity caused by half-cycle ambiguities in dy-namic environments,a stepwise Beidou triple-frequency partial ambiguity resolution method is proposed.Initially,based on the characteristic of half-cycle ambiguity,a continuous observation epochs partial ambiguity resolution(COE-PAR)method is designed to preliminarily select high-quality ambiguity subsets.This method reduces the computational load for subsequent partial am-biguity resolution.Furthermore,a cascading partial ambiguity resolution(CPAR)method is de-signed.This method employs multiple screening methods based on observation quality to sequen-tially fix the ambiguities of extra-wide-lane,wide-lane,and narrow-lane.Then,the partial ambi-guities free from half-cycle ambiguities are fixed.Ultimately,the effectiveness of these methods is validated through dynamic vehicle-mounted experiments.The experimental results demonstrate that the stepwise Beidou triple-frequency partial ambiguity resolution method can effectively en-hance the ambiguity fixing rates for kinematic-to-kinematic relative positioning.In urban dynamic environments,compared to traditional full ambiguity resolution method,the ambiguity fixing rates,validated by Ratio test,are improved from 91%to 100%,and the relative positioning errors are reduced by 18%to 79%.Moreover,the COE-PAR method reduces the execution times of the least squares ambiguity decorrelation adjustment(LAMBDA)method during ambiguity exclusion in the CPAR method by approximately 55%.