A design method integrating cognitive loads is proposed to optimize the interfaces of project management systems and improve the usability of the interfaces. This method combines objective cognition laws with subjective cognition of users to form layout design principles and then transform them into a calculable multi-objective optimization function for interface layout. On this basis, the sparrow search algorithm (SSA) encodes the objective function to seek the optimal solution in space and obtain the layout optimization plan. The homepage of a railway project management platform is taken as an example to verify the effectiveness of the method in this study. Specifically, apart from the optimization of the proposed method, the physiological measurement method of eye movement is introduced into the evaluation process, and the usability test is carried out to measure eye movement loads. The experimental results show that the optimized interface layout has been significantly improved regarding the interface usability index, which proves the effectiveness and practicability of the method.