The use of in-situ lunar resources to prepare structural materials is an important method of reducing the construction cost of lunar bases. On the basis of preparing simulated lunar regolith, the physical and mechanical properties of radiation sintering hardened simulated lunar regolith were studied. The results indicate that using volcanic slag as raw material, the preparation of simulated lunar regolith can be achieved through processes such as drying, impurity removal, crushing, and screening. The prepared simulated lunar regolith exhibits good similarity with real lunar regolith and existing simulated lunar regolith in terms of microstructure, particle size distribution, chemical composition, mineral composition, etc. Simulated lunar regolith hardening was achieved through radiation sintering, and the effects of sintering temperature and particle size distribution on the apparent density, sintering shrinkage, and mass loss rate of hardened lunar regolith were studied. The mechanical properties of hardened simulated lunar regolith were determined through monotonic compression tests, and the sintering temperature and particle size distribution of simulated lunar regolith had a significant impact on the mechanical properties of sintered hardened lunar regolith. Before the monotonic compression test failure, the specimen did not undergo significant plastic deformation. The elastic modulus did not change significantly, approaching the ideal linear elastic material. The variation patterns of elastic modulus, compressive strength, and ultimate strain of sintered hardened lunar regolith with different key parameters were discussed.