Lunar regolith simulant (LRS) geopolymer is formed through alkali activation and exhibits advantages such as high in-situ resource utilization, excellent resistance to extreme temperatures, effective radiation shielding, and high durability. Research on LRS geopolymer contributes to the development of in-situ resource-based lunar construction. The effects of ball-milling time and curing temperature on the early mechanical properties and microstructure of LRS geopolymer were investigated. Scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FT-IR), and ²⁹Si magic angle spinning nuclear magnetic resonance(²⁹Si MAS-NMR) were employed to analyze the micro-morphology, phase composition, infrared absorption characteristics, amorphous structure, and solidification mechanism of the geopolymer. The results show that with a curing age of 48 h and a ball-milling time of 80 min, the compressive and flexural strengths of LRS geopolymer reach maximum values of 28.39 MPa and 1.81 MPa, respectively. At a curing temperature of 80 ℃, the compressive and flexural strengths are 38.86 MPa and 3.16 MPa, representing increases of 1 750.47% and 444.83%, respectively, compared to those cured at 40 ℃. Microstructural analysis indicates that increased ball-milling time and curing temperature promote the dissolution, migration, and polymerization of SiO₂ and Al₂O₃ in the geopolymer. In addition, the reaction efficiency is enhanced, leading to increased formation of hydrated gel products that rapidly fill the pores between LRS particles, resulting in a denser geopolymer structure and improved mechanical strength.