The invention provides a robot autonomous navigation method and a robot autonomous navigation system, which relate to the technical field of robot navigation. The method comprises steps: a virtual path is made in advance for the navigation space, wherein the virtual path is composed of coordinate points and a connection relationship among the coordinate points; the initial position and the destination position of the robot in the navigation space are acquired, and according to the initial position and the destination position, initial coordinate points and destination coordinate points of the robot in the virtual path correspondingly are determined; a path planning algorithm is adopted to calculate the shortest path from the initial coordinate points to the destination coordinate points in the virtual path; and according to the shortest path, the robot is guided to arrive at the destination coordinate points. The robot can smoothly arrive at the navigation destination without a high-precision sensor, the robot cost is reduced, the robot autonomous navigation system complexity and the calculation amount during the navigation process can be reduced, and the robot autonomous navigation system reliability is improved.