Pressure sensors are used in the field to measure WOH, casing pressure and SPP. The sensors have used advanced Wheatstone bridge made of pressure-sensitive elements; under constant voltage power supply conditions, for the compressive resistance effect of silicon material, the bridge circuit output is directly proportional to the direct voltage or standard 4 - 20mA current signals of the sensed pressure. The corrosion preventive membrane barrier and totally enclosed stainless steel crust are installed outside the semiconductor pressure sensitive piece of the sensor; it has the advantages of small temperature coefficient, good waterproofing corrosion resistance, high accuracy, big output signal, good repetitiveness and stable performance, etc.; it is suitable for dirty working environment in the field of petroleum industry.