Thefuture construction of the lunar base advocates the full use of the lunarmaterial resources for the construction of the lunar surface. In this paper

graphene oxide (GO) and nano-SiO(NS) were added to lunar regolithsimulant geopolymer by ball milling and ultrasonic dispersion to prepare lunarregolith simulant geopolymer nanocomposites (LRSGN). The mechanical propertiesof LRSGN under high temperature curing environment of the moon were studied.The surface crack deformation and strain evolution distribution characteristicswere analyzed by digital image correlation (DIC) technology. The microstructureevolution was characterized by X-ray diffraction(XRD)

Fourier transforminfrared spectrometer(FTIR)

mercury intrusion porosimetry (MIP) and scanningelectron microscope (SEM). The results show that the addition of GO and NSsignificantly improve the mechanical properties of LRSGN

and the optimumcontents are 0.08% and 1%

respectively. The maximum compressive strength ofthe 28 d samples mixed with GO and NS in the lunar regolith simulant byultrasonic dispersion were increased by 93% and 145%

the maximum splittingtensile strength were increased by123% and 219%

and the maximum flexuralstrength were increased by 64% and 144%

respectively

compared with thecontrol group. The enhancement effect of mechanical properties is much betterthan that of ball milling dispersion. The proper incorporation of GO and NSwill also delay the formation of local strain concentration zone of LRSGN. Themaximum principal strain is at the crack of the sample surface and appears inthe form of local strain concentration zone. The microstructure results showthat GO and NS have nucleation effect

filling effect

size effect and bridgingeffect

which promote the polymerization reaction in the system and improve theoriginal pore characteristics

thus improving the mechanical properties of thesamples. However

with the increasing content of GO and NS

the agglomerationeffect of nanomaterials will occur

which is not conducive to the developmentof LRSGN strength. These findings provide a theoretical basis and experimentaldata for material selection and structural design of lunar engineering.