Mobile gravity measurement is important in metrology, earth science, national defense, etc. The atom gravimeter has good technical potential in mobile and high precision gravity measurement. However, it is still difficult to achieve both high integration and high sensitivity. In this article, a vehicle gravity measurement system based on the atom interferometer is developed. Based on the miniaturized and highly integrated instrument design, the high precision gravity measurement in the field could be achieved. The sensitivity is 520 μGal / Hz for outdoor gravity measurement and the measurement repeatability is better than 20 μGal Then, we carry out a rapid gravity measurement on a field survey line with a length of 10 km and an elevation change of 100 m. The gravity measurement results are compared with the LG-1 relative gravimeter. The debugging time of each point is less than 5 min, and the effective measurement time is less than 15 min. In the general field environment, the measurement residuals of two gravimeters are less than 100 μGal, and the residuals of the designed vehicle gravimeter are less than 15 μGal. Therefore, this vehicle-mounted gravity measurement system greatly improves the efficiency of field gravity mapping. It is convenient for transportation and has fast and accurate measurement. In general, the instrument provides a reliable technical solution for the field of mobile gravity measurement.