Aiming at the problems of serious pollution and low efficiency associated with the traditional roasting process for treating low-grade, high-sulfur and refractory gold concentrates, a combined process of oxygen pressure water leaching and cyanidation was proposed. The process parameters were systematically optimized, and the leaching mechanism was investigated. The effects of the process on gold recovery were evaluated through process mineralogical analysis and cyanidation experiments. The results show that under the optimal conditions of temperature of 180 ℃, oxygen partial pressure of 1.5 MPa, leaching time of 120 min, stirring speed of 700 r/min and liquid volume to solid mass ratio of 200∶1, oxygen pressure water leaching can effectively oxidize pyrite and other sulfide minerals into hematite, thereby destroying the encapsulated state of gold. After pretreatment, the gold grade in the leaching residue increases from 42.24 g/t to 63.78 g/t, with an enhancement of over 50%. Process mineralogical analysis indicates that gold is released from sulfides, occurring in exposed or semi-exposed states. The mineral structure becomes loose and porous, and the gold exposure significantly increases, providing a more favorable reaction interface for subsequent cyanidation. Cyanidation experiments further confirm the pretreatment effect, achieving a maximum gold leaching rate of over 99.50%, along with a marked reduction in cyanide consumption. These results demonstrate that oxygen pressure water leaching is an effective pretreatment technology for improving the gold recovery and reducing reagent consumption in low-grade, high-sulfur and refractory gold concentrates, providing technical guidance for the efficient and environmentally friendly utilization of such resources.