［Objective］ The effects of gravel on the moisture infiltration characteristics of excavation spoil in highly weathered dolomite tunnels were investigated， in order to provide a scientific basis for evaluating the stability of safe spoil disposal sites while excavating large-scale water diversion tunnels. ［Methods］ Indoor simulated soil column infiltration experiments were conducted using a one-dimensional vertical constant-head infiltration method， with gravel-free conditions as controls （CK）. This study examined the movement of the wetting front and variations in moisture infiltration rates with three gravel particle sizes （2—5， 5—10， 10—20 mm） and four gravel contents （10%， 20%， 30%， and 40%） in a highly weathered dolomite excavation spoil， while also fitting and assessing the applicability of the infiltration processes. ［Results］ Compared to the CK treatment， including gravel in the spoil significantly reduced the depth of the wetting front movement， moisture infiltration parameters， and cumulative infiltration amounts under identical time conditions. The initial， steady， and average infiltration rates and the cumulative infiltration amounts decreased by 17.34%—68.67%， 6.45%—51.94%， 28.51%—73.06%， and 6.74%—49.42%， respectively （p<0.05）. Gravel had a significant hindering effect on the moisture infiltration process in the spoil， with particle size showing no significant influence （p>0.05）. Meanwhile， gravel content had a significant impact （p<0.05）. As the gravel content increased， the suppression of moisture infiltration showed a threshold effect. When the gravel content surpassed 30%， the changes in the moisture infiltration parameters became non-significant with further increases in gravel content （p>0.05）. A comprehensive analysis of the fitting degrees of the three typical infiltration models and the physical significance of the simulated parameters indicated that the Horton model was more effective than the Kostiakov and Philip models in simulating moisture infiltration in a highly weathered dolomite excavation spoil. ［Conclusion］ The gravel content was a primary factor in suppressing moisture infiltration in highly weathered dolomite excavation spoils. The Horton model showed the best applicability for fitting the infiltration process.