Abstract: In order to get an accurate simulation of the complex three-dimensional unsteady flows in turbomachine, an in-housed unsteady turbomachinery simulation program is developed based on a petaflops high performance computing platform. The full annulus grid simulation method has been developed. The conservative variable interpolation method for sliding interfaces and the high efficient massive parallel computation scheme are discussed in detail. A single stage compressor, a 1.5 stage turbine, and a 3.5 stage high-loaded compressor were simulated to verify and validate the program. The parallel efficiency of the program was also tested. The maximum grid number of the testcases is approximately 200 million, and the number of CPU cores is up to 4096. The results show that aerodynamic performance computed by this program agrees well with experimental data. The full unsteady computation method adopted in this paper guarantees variables' continuity at the sliding interface, weakens nonphysical entropy generation, and yields a reasonable flowfield. The grid partition methods by METIS and the parallel program scheme of MPI contribute to the program with a good load balance and a high parallel efficiency. This program has good expansibility and adaptability to the complex problem of large scale and satisfies the need of complex application flow analysis and exquisite turbomachiney flow filed study.