A signal processing method which is used for sensor based on dif-hight is introduced.This sensor uses liquid as medium to transmit pressure.A meter amplifier is used as a prepositive amplified circuit.The signal circuit is designed to carry out amplify and filtering function.A combination of sofware and hardware were used to process the data by computer.As a result
the circuit is simplified
and the system cost is decreased.The feasibility of the circuit are verified by the experiment.