A system of paper quantity measurement based on FDC2214 capacitive sensor is designed.The system collects capacitance value information of different paper quantities by capacitive sensor chip

and send the digital frequency value to the micro controll unit（MCU）by I~2C

and perform digital filtering and data processing and calculating

according to the model established by the experimental data

thereby converting the capacitance value signal into the paper quantity.Achieve the function of measuring different paper quantity.The experimental results show that the comprehensive accuracy of the measurement of 8 groups of different paper groups reaches 94.38%.