Because of the existence of dangerous-rock collapse in the protection zone of the cultural relic site of Huashan rock art, the safety of visitors and the integrated conservation of the rock painting have been seriously threatened. In order to evaluate the states of the dangerous rock and provide a scientific basis for the later-stage conservation, by investigating of the geological condition and the cause of the geological hazard, the author analyzes the factors that influence the formation of the dangerous-rock and the mechanism of slumping and summarizes that there are three patterns of slumping, including unstable toppling, staggered breaking and pull-splitting land failure. The stability of partial dangerous-rock with different damaged patterns was calculated with the method of limit equilibrium. According to the calculation, most of the dangerous-rock was under an instable situation, and needed to be renovated. Finally, some measures and principles were put forward to prevent and restore the dangerous-rock.