Considering the high-pressure inside and the launch and Mars entry environment, the Rover cabin was based on the design of the ISS habitation module, and the skin-stringer structure design was proposed. In order to propose a realistic design of a cosmic radiation shielding Rover, UHMWPE composites were proposed as a Rover skin structure. The thermal environment while the Rover was being transported to Mars was reviewed through relevant documents, with the result that 125°C was set as the temperature for the space environment test. PUR and acrylic resin were selected as suitable matrix for UHMWPE composite through space environment tests. The SEM image confirmed that the microcracks of fibers and matrix increased after the space environment test. Therefore, it was predicted that the mechanical properties would deteriorate after the space environment. In the results of proton irradiation tests and OLTARIS analysis through elemental composition, UHMWPE composites showed cosmic radiation shielding performance comparable to PE. Based on conservative career effective dose limits (permissible dose limits) design specifications, the GCR dose on the surface of Mars is designed to expose astronauts to effective doses of 145 to 163 mSv/year, which is the limit dose for women between the ages of 35 and 40. Therefore, the thickness of UHMWPE composite as Rover outer wall was proposed to be 1 ~ 7.5 g/cm2. It is expected that UHMWPE composites will be applied to future Mars exploration vehicles.