Abstract: Aiming at solving the problem of large errors for INS/GNSS integrated navigation system with low cost MEMS-IMU device, during loss of GNSS signal, a low-cost vehicle INS/GNSS integrated navigation system based on assistance of vehicle non-holonomic constraints is studied. The vehicle non-holonomic constraints are simplified for the low-cost characteristics of the system, and the model of the filtering algorithm is derived accordingly. The results of simulation analysis and on-board testing show that, for the low-cost INS/GNSS integrated navigation system composed of consumer-grade MEMS-IMU and GNSS receiver, during 1min loss of GNSS signal, the navigation position error is less than 3% of the driving distance, after adding the assistance of such simplified vehicle non-holonomic constraints. The application of such constraints can significantly improve the accuracy of low-cost vehicle INS/GNSS integrated navigation systems.