The invention relates to a polyurea metal salt composite bearing lubricating grease composition and a preparation method thereof. The composition comprises the components by the percentage: 10-20% of a dipolyurea metal salt thickening agent, 75%-85% of base oil, and 1.5-5% of an additive including (a) 0.5-4.0% of an aromatic amine and/or phenol antioxidant and (b) 0.5-2% of a phosphorus-series antiwear agent. With use of polyurea as the thickening agent, the composition has better oxidation resistance, so as to ensure longer lubrication period; at the same time, the composition has outstanding high-temperature performance and relative wide applicable temperature range; due to introduction of metal elements, the extreme pressure antiwear performance of the polyurea lubricating grease is greatly improved, and the polyurea lubricating grease can be applied to an occasion having relatively high requirement on the extreme pressure antiwear performance. Through composite of the metal salt and the polyurea thickening agent, the polyurea lubricating grease product used at a relatively high load environment and having the advantages of excellent extreme pressure antiwear performance and good high and low temperature fluidity, anti-rust performance and antioxidant performance is provided.