High pile cap foundation is an important component of the supporting structure system for offshore fixed wind power. Due to the harsh marine environmental conditions, the development of high durability foundation caps is of great significance for improving the long-term service performance of the structure. Ultra high performance concrete (UHPC) has high strength and durability characteristics, and has superior application advantages in high-performance engineering structures. This paper proposes a high performance composite bearing cap structure using ultra-high performance concrete as a membrane shell without disassembly. The mechanical behaviors and failure mechanism are analyzed by numerical simulations under the serviceability limit state (SLS) and over-design state (ODS). The results show that the high performance composite bearing cap has better mechanical and deformation properties and excellent economic benefits compared with the normal conrete bearing cap.