With the development of mobile robots, fast and accurate path acquisition becomes increasingly important. Traditional path planning methods treat the mobile robot as a prime and do not consider the kinodynamic model of the mobile robot, which often leads to the collision of the mobile robot with obstacles. Meanwhile, since obstacles always change dynamically in real scenarios, this poses a great challenge to the motion planning of mobile robots. We propose a fast RRT* method based on the kinodynamic model, which introduces a mobile robot kinodynamic model by introducing an artificial potential field to accelerate the path. Meanwhile, the kinematic constraints of the mobile robot to the motion trajectory, and the dynamics constraints of the mobile robot to avoid collision between the mobile robot and the obstacles are considered. Through experimental results, we demonstrate that our method can effectively deal with the kinodynamic characteristics of mobile robots in real scenarios.