In this paper, according to the reality that there is no mature Chinese national design criterion but partial enterprise standard for rock bolt crane girder in the underground powerhouse of large hydropower station up to now. Based on the geological conditions, the rock bolt crane girder was designed by using method of rigid body equilibrium. The reinforced anchoring measures for rock bolt crane girder in undesirable geology were studied subsequently by the experience of analogous projects. The stability of rock bolt crane girder in underground powerhouse was analyzed and evaluated by Finite Element Method (FEM). Then the bearing capacity of crane beam was researched by means of bearing testing. The results show FEM is practicable to evaluate the stability of the rock bolt crane girder and to guide the rock bolt crane girder designing. The results also show the reinforced anchoring measures are appropriate to displace the undesirable surrounding rock section by using concrete. The results of bearing testing show that the design of rock bolt crane girder and its anchoring measures are rational, and crane girder can meet to the requirement of safe operation.