The invention discloses a method for planning an optimal path for incremental environment information sampling of an indoor mobile robot. The method comprises the following steps: (1) acquiring surrounding environment information, and establishing obstacle collision risk-based evaluation probability; (2) planning a path by utilizing an optimal path planning algorithm for the incremental environment information sampling; (3) enabling the indoor mobile robot to select the path and enter a new path planning process. By adopting the optimal path planning algorithm for the incremental environment information sampling, the current optimal path can be planned in real time according to the current conditions of the indoor mobile robot and the inherent nonholonomic constraints of the robot; meanwhile, a collision detection environment in a search tree extension process is optimized; the planning efficiency is improved; the indoor mobile robot can reach a specified position quickly and safely.