In order to improve the serious flickering problem of the laser scanning projection system caused by the scanning frequency much smaller than 20 Hz when scanning complex graphics,we applied the Fleury algorithm to the laser scanning projection path planning based on the graph theory, and proposed a novel improved Fleury algorithm for the limitations that the previous algorithm could not optimize the non-Eulerian paths.We simulated and analyzed the scanning path optimization effects of the above algorithm by MATLAB, and applied it to the existing laser scanning projection system for experiment furthermore.Experiments results show that, the laser scanning projection path optimization technology based on the improved Fleury algorithm can increase the frequency to around 20 Hz, effectively solve the flickering problem,it can also improve the quality of the drawn graphics, thus enhancing the practical application value of the self-developed laser scanning projection instrument.