Abstract A kind of applies to quiet displacement measurement , the high-accuracy electricity eddy detecting technology that the vibration shaking the displacement measurement , monitoring a rotation shaft in revolution machinery measures measures displacement method that the main body of a book has been submitted. System having introduced the electricity eddy distance measurement realizing that method with monolithic machine, system collects a circuit from the AT89C51 monolithic machine , electricity eddy sensor displacement , ADC0804A/D change-over circuit , 1602 liquid crystal display circuits are composed of. The displacement signal collects , enlarges after UA741 the queen from electricity eddy sensor, the modulus converter changes into figure amount from ADC0804 , carry out acquisition from monolithic machine , realize the tiny displacement under the control of among 2 o'clock thereby. Demonstrate displacement by LCD display. This system has merit such as easy operation , distance measurement accurate degree height and the perception demonstrating result. Keywords: Electricity eddy sensor; AT89C51 monolithic machine; Displacement is measured; 1602 liquid crystal