Multi-block structured mesh is widely used in high-precision aerodynamic simulation, but mesh blocking usually requires substantial manual intervention, which is time-consuming and demands a high level of user expertise. In this study, a potential field-based blocking algorithm for structured mesh generation around an aircraft is proposed, and a corresponding multi-block grid generation workflow is established. First, an unstructured mesh is generated in the computational domain using commercial software, and the potential field is constructed by solving the Laplace equation for the potential function with appropriate boundary conditions. Next, the gradient lines in the potential field are calculated, and the surfaces of the hexahedral blocks are determined to divide the computational domain. Finally, the structured meshes are generated within each block. Two aircrafts, the canard missile and the transport aircraft, which feature slender winged body-of-revolution configurations, are used as test cases to assess this method. The quality parameters of the generated grids and the aerodynamic simulation results are compared with those of officially published benchmark grids. It is demonstrated that the proposed method significantly improves the mesh generation efficiency and yields multi-block structured meshes of good quality. Compared with the benchmark meshes, the generated meshes exhibit better convergence characteristics. In addition, the calculated aerodynamic coefficients with the two sets of meshes are similar and in good agreement with the experimental data.