Human resources are the most dynamic and creative factors in the production factors of engineering projects, and human resource allocation is the key link to whether human resources can give full play to their roles. This paper discusses the realization strategy of optimal human resource allocation for engineering projects and designs a human resource optimization allocation scheme for multiple engineering projects based on the key human resource element of the project manager. Firstly, it constructs the engineering project manager competency element index system and engineering project priority evaluation index system and applies a multi-level fuzzy comprehensive evaluation method to evaluate project manager competency and engineering project priority ranking, respectively. Finally, taking an engineering and construction company as an example, using a linear programming model, an empirical study of human resource allocation for engineering projects is conducted. In the human resource allocation scheme of the optimization model constructed in this paper, all 30 project managers are assigned to 10 projects to meet the staffing needs of all projects within the planned construction period, and the total labor cost is 5.897 million yuan, which is smaller than the 6.192 million yuan of the traditional allocation scheme. It shows that the multi-project staffing model proposed in this paper can ensure the project staffing needs while completing the staff allocation with the lowest total labor cost, which is more effective compared with the traditional staffing methods.