The system is controlled by AT89C51 single chip microcomputer as the core, and is composed of self-made capacitive sensor, counting circuit and display circuit. The paper is placed between the two plates of the capacitive sensor to make the dielectric constant of the capacitive sensor change. The detection circuit is connected with the two plates of the capacitive sensor through two shielding wires to collect the changing pulse signal and generate the square wave signal with stable period through the oscillation circuit. Square wave enters the MCU to compile and count, and finally the digital tube displays the number of paper in a short time.The system is easy to control and operate, and can be used for small and medium-sized paper counting.