Facing the challenges of the next generation exascale computing, National University of Defense Technology has developed a prototype system to explore opportunities, solutions, and limits toward the next generation Tianhe system. This paper briefly introduces the prototype system, which is deployed at the National Supercomputer Center in Tianjin and has a theoretical peak performance of 3.15 Pflops. A total of 512 compute nodes are found where each node has three proprietary CPUs called Matrix-2000+. The system memory is 98.3 TB, and the storage is 1.4 PB in total.