The Bianjiadayuan Pb-Zn-Ag Deposit is located in southern Da Hinggan Mountains and at the northern edge of Xar Moron deep fault. The main styles of mineralization are veins and crypto-explosive breccia. The ore veins are mainly developed in the contact zone between granodiorite and wall rock. Crypto-explosive breccia occurs in the upper part of the granodiorite. Based on the geological characteristics and an analysis of the testing data, the authors hold that the Bianjiadayuan Pb-Zn-Ag deposit is a mesothermal magmatism-hydrothermal deposit.