The invention relates to a tibial plateau back outer side bone plate and belongs to the field of medical apparatuses and instruments. The tibial plateau back outer side bone plate is mainly used for tibial plateau high-energy damage with back outer side fracture collapse. The tibial plateau back outer side bone plate comprises a tibial plateau back outer side bone plate body (1), a phi 3.5 locking screw (2) and phi 3.5 ball head screws (3). During an operation, a back outer side operative incision is formed, important vessels and nerves are protected, fracture is exposed, embolia is carried out, an operation position is cleaned, the specifications and the number of tibial plateau back outer side bone plate bodies and screws needed in the operation are determined, the operation is carried out, the tibial plateau back outer side bone plate body (1), the phi 3.5 locking screw (2) and the phi 3.5 ball head screws (3) are implanted and are fixed at the position required by the operation, and the purpose of the operation is achieved.