Pile foundation is widely used in the complicate geological condition in covered karst region, and composite foundation can be adopted when the overburden thickness is enough. Recent years witnessed the increasing use of rigid pile foundation to reinfore the vital structure that the settlement is controlled strictly. The karst geological condition, the design and construction, and the settlement observation result of the low-grade plain concrete pile composite foundation for the Longgang Culture Center in Shenzhen is expounded in details. It shows that this composite foundation technology is ad-visable in karst region, and can be a feasible treatment for similar engineering.