Abstract: The utilization of in-situ lunar resources has become the core path for the construction of lunar scientific research stations. This paper adds multi-walled cabon nanotbes (MWCNTs) and basalt fibers (BF) into basalt-simulated lunar soil to study the mechanical properties of reinforced lunar soil simulant geopolymers. In uniaxial compression and three-point flexure tests, the digital image correlation (DIC) technology was used to detect the horizontal strain evolution process on the surface of the sample, and the hydration products and microstructure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results show that the compressive and flexural strength of the geopolymer can be significantly improved when the mass content of MWCNTs and BF is 0.10 % and 0.40 % respectively. In the process of compression and bending failure, the geopolymer presents the stage of crack initiation, development and penetration, and the incorporation of fibers can effectively delay the initiation of the strain concentration area of the sample and the development of internal cracks. The fibers play a role of filling, bridging and nucleation in the geopolymer, and the structural compactness is enhanced, thereby improving the mechanical properties of the geopolymer.