Nowadays， with the power system's increasingly high requirement on operation information visualization， the importance of electric equipment information for the whole life cycle management， remote fault diagnosis， and 3D visualization is increasing with each passing day. Based on the object-oriented 3D information model and the power enterprise common information model（CIM） while taking the transformer information model as an example， a 3D information model package of electric equipment in CIM for the electric transformer is constructed and an object-oriented common information model in 3D（OCIM3D） is presented. Finally， the OCIM3D for electric transformer is developed， by which the process of OCIM3D modeling is described and implemented. The experimental results show that the OCIM3D for electric equipments modeling is feasible and universal.