In order to further improve the automation degree of computer-aided design in garage design, a set of program algorithm for automatic parking arrangement was written based on Dynamo visual programming by analyzing and capturing one of the most commonly used design ideas of designers and simulating the traditional operation process. The results shows that for each test model, when the design conditions are the same and the designer and the computer adopt the same algorithm, the result of manual arrangement is consistent with the result of computer generation. The program′s operation efficiency, stability, accuracy and rationality of operation results, and the convenience of operating procedures have basically met the expected results of the study.