In the process of ship painting, the distribution of coating thickness and its calculation is difficult due to the complexity of the coating formed by manual spraying. Therefore, a modeling and simulation method of manual spraying based on virtual reality (VR) is proposed. The manual spraying model (MSM) is established by the relationship between gun parameters, position, direction, and coating thickness. Then the MSM is verified by designing a spraying test. The results show that the simulation and test error is less than 8%, which proves the accuracy of MSM in this paper. Based on the MSM, a VR-based ship spraying simulation scene was developed using C# and Unity3D, and the error was less than 5% by comparing it with the coating thickness of the actual test. This further illustrates the reliability of the MSM in this paper.