Located in eastern Central Asian orogenic zone, the Olji area belongs to the lead, zinc, silver, copper, tin, iron metallogenic zone of southern Da Hinggan Mountains. Permian Dashizhai Formation in the study area is an association of metamorphic volcanic rocks interbedded with clastic sedimentary rocks. The volcanic rocks have the characteristics of typical asymmetric bimodal volcanic rocks, and the basic peak is strong. The study of rock geochemistry indicates that intermediate-basic and intermediate rocks belong to quasi-aluminous and calc-alkaline rock series or low potassium (tholeiitic) rock series, intermediate rocks belong to shoshonitic rock series, and intermediate-acid rocks belong to peraluminous and calc-alkaline rock series. The rocks were formed in an island arc environment of continental margin rift basin in middle-late Hercynian period. Dashizhai formation volcanic rocks are enriched in Ag, Sn, Pb, Zn, Cu and other metallogenic elements, and constitute the source bed of Pb, Ag, Sn, Zn and other metallogenic elements in the study area. The metallogenic potential of Dashizhai Formation volcanic rocks is huge. Combined with previous research, the authors hold that Dashizhai formation volcanic rocks are the best place in search for volcanic hydrothermal lead-zinc-silver-copper deposits.