In order to achieve the locating and navigation functions of the indoor mobile robot in the unknown environment, we designed an indoor mobile robot which based on robot operating system (robot operating system, ROS). We studied the method of building grid maps and cost maps incrementally, and the adaptive Monte Carlo locating and navigation method, and path planning method which using Trajectory Rollout and Dynamic Window algorithms. The results of test show that the designed autonomous navigation and location software can incrementally draw the environment map, and the planned path is the optimal path. When the robot walks in the room according to the planning path, location accuracy can reach 10 cm and deflection accuracy can reach ± 5° which can achieve the locating and navigation functions of the indoor mobile robot in the unknown environment.