Focused on low accuracy in vehicle trajectory matching and traffic flow data errors, when low-frequency collection approach was used during the survey of urban road traffic flow and traffic data collection of particularly at critical road network nodes. A vehicle trajectory reconstruction method was proposed based on the study of the hidden Markov theory and the minimum cost maximum flow model. Using multi-source data fusion technology and geographic information positioning matching technology, the missing traffic basic data of the non-detector road section were reasonably estimated to provide important data support for the research of vehicle trajectory reconstruction. Then, a high-frequency trajectory point dataset of taxi vehicles in a specific region of Chengdu City was employed to validate the effectiveness of this method. The results demonstrate that the complete coverage rate of trajectory reconstruction using low-frequency vehicle trajectory points reaches 89.4%, confirming the method's efficacy and practicality.