Abstract: The mission trajectories of the Chang’E-5 are complicated with many constraints. Selecting a sampling area is largely determined by inseparable from the trajectory design. In this paper, the sampling area selection method based on the orbital geometry in the Chang’E-5 mission was first proposed and practiced. This method is constrained by principles of the most compact task schedule, the least fuel consumption, the most launch opportunities, and other requirements for sub-systems. First, the feasible sampling area range with the least of engineering implementation cost is calculated. And then the final sampling area range is determined by comprehensively considering the topographic safety and scientific value. Compared with the traditional method, this method considers the strong coupling between the location of the sampling area and the mission trajectory, which is unique to the lunar sampling return mission Besides, this method determines the location and range of the sampling area from the aspects of feasible engineering implementation and wide adaptability, thus ensuring the optimality and wide adaptability of the mission plan. Due to the launch vehicle, the established launch window has been postponed from 2017 to 2020. The designed sampling area range is updated to the new launch date, ensuring that the mission trajectory design remained unchanged. The design laid a solid foundation ensuring the complete success of the Chang’ E-5 Mission.