The invention provides a path finding method based on an A star optimization 
algorithm. The method comprises the steps of: giving a grid chart of a map, determining the position coordinates of a corresponding obstacle point, and determining the coordinates of a starting point and a target point, constructing a linear function between the starting point and the target point, solving a key point where a straight line intersects with the grid, then solving related adjacent nodes, and judging whether nodes coinciding with the obstacle point exist in the nodes or not, if the node does not coincidewith the obstacle node, enabling the searched optimal path to be a straight line between the starting point and the target point of the automobile, if an obstacle point is encountered, internally calling an A star 
algorithm, and putting non-obstacle nodes around the point into an open 
list, judging whether the open 
list is empty or not, taking a point with the smallest f value out from the open 
list to serve as the next step of path finding, judging whether the point is a target point or not, and if so, determining that path finding succeeds and ending the 
algorithm, or otherwise, continuing path finding, setting the point as the 
current point, and continuing the path finding process. According to the method, the algorithm is optimized by preprocessing the obstacle, so that the node searchtime is shortened, and the calculation memory is reduced.