Introduces the working principle, the hardware circuit and the system software design of the High Performance Downhole Gauge System, based on 89C2051 single chip microcomputer?sputtered metal film pressure transducer?DS18B20?AD7714?and AT45D081A. The gauge can be widely applied in pressure measurement of various fluid mediums where the working pressure is under 60MPa and the working temperature is between-40℃ and 85℃.