Abstract: In order to improve the service performance of grid network real-time kinematic (RTK) and eliminate the impact of terrain on positioning accuracy, the paper derived a grid RTK positioning error model with terrain elevation difference based on grid network RTK technology, and selected three regions of plain, transition areas and mountainous areas to carry out grid RTK positioning experiments with different grid densities, analyzed and determined the grid density standards for different terrain. The results show that the higher the density of grid, the higher the positioning accuracy of grid RTK, while under the same grid density, the positioning accuracy of plain, transition areas and mountainous areas decreases step by step due to the impact of terrain elevation difference. When 9'×9', 6'×6' and 3'×3' grids are used in plain, transition areas and mountainous areas, positioning accuracy of 1 cm can be achieved. It can provide the corresponding basis for setting the grid partitioning criterion.