Aiming at the problem of interfere in the process of multiple robot fish heading the ball in the underwater robot competition, a ball-pushing algorithm of multiple robot fish collaboration based on finite state automata is introduced. Consider the characteristics of the robot fish’s movement and the water environment, and based on the ball-pushing algorithm of single robot fish, this paper establishes the mathematical model based on the finite state automata, and plans each robot fish’s decision-making of the action. Thus each robot fish can achieve their path planning efficient without interfere with each other, so that multiple robot fish can achieve the effect of ball-pushing efficient. The result of tests shows that the finite state automata can trigger the status conversion of each fish and they can push the ball without interference, and greatly improves the efficiency in the process of multiple robot fish heading the ball.