The invention belongs to the technical field of lubricating grease preparation and provides composite barium-urea lubricating grease and a preparation method thereof. By selecting normal industrial materials and adopting a simple preparation method, carboxylic acid barium salt is introduced into polyurea molecules to prepare the composite barium-urea lubricating grease. The composite barium-urea lubricating grease is good in adhesion and extreme pressure antiwear property, has long bearing life particularly at high temperature, and has great popularization and application value. On the premise of good performances of the composite barium-urea lubricating grease, production cost is controlled, application range of polyurea grease is widened, and technical process for the preparation is simple.