Abstract: The lunar residency and the extra-vehicular activities of astronauts depend very much on the protection of the lunar EVA spacesuit. In view of the special requirements of various constraints on the spacesuit for manned lunar landing missions, the overall conceptual design of the spacesuit for the lunar landing is carried out from the point of the clothing process design to meet the adaptability of the environment. The model based systems engineering (MBSE) method is used to build a lunar EVA spacesuit model by the SysML, with a dual-purpose design philosophy for both in-cabin and on-the-moon use. The detailed conceptual design is described part by part, including the helmet, the main body of clothing, the gloves, the boots, the life support package, as well as the reliability and the security. The related design ideas and schemes may serve as a reference for the EVA spacesuit design for the manned lunar landing or even further planet landings.