Abstract: The detection of the solar system boundary has gradually attracted people's attention. To explore the solar system boundary, we need to find an efficient propulsion system and design a reasonable trajectory to escape from the solar system. Therefore, this paper proposes to use the Bezier shape-based method to quickly generate the three-dimensional trajectory of the electric sail escaping from the solar system, which provides an appropriate initial solution for a more accurate trajectory optimization algorithm. By taking the results obtained by the Bezier shape-based method as the initial solution of Gauss pseudospectral method（GPM）, the applicability of the results obtained by the Bezier shape-based method to the initial solution of the direct solver is evaluated. The simulation results show that the Bezier shape-based method can design a reasonable three-dimensional initial trajectory of the electric sail escaping from the solar system for the direct optimization solver in a short time. This is of great significance for the rapid evaluation of a large number of electric sail flight scenarios in the preliminary mission design stage.