The invention discloses an ACO-based ROS robot global path optimization method. The method comprises the steps of setting ant colony algorithm initial parameters; modeling an environment map by utilizing a grid strategy, selecting a preferred area according to a starting point and a target point to increase a pheromone initial value, and performing differential increment setting on pheromones in combination with the sum of distances between nodes and the starting point as well as the target point and the distance proportion; searching an optimal path, initializing a tabu table, adding the tabutable into the starting point, searching a next reachable node by utilizing a state transition probability, and stopping searching until the node selected by the ant is a target point; judging whether the loop iteration frequency reaches a preset value or not, if so, storing information, and if not, continuing path search; and ending until the optimal path is found. According to the method, the convergence rate and the optimization effect of the algorithm are greatly improved, and the effectiveness and feasibility of the improved ant colony algorithm for solving the robot path planning problem are verified through MATLAB simulation experiments.