At present,indoor positioning technology has a key impact on people’s daily production and life. Sensors are one of the keys to this technological breakthrough, and sensors based on different technologies have become the focus of attention of researchers. For instance,imaging techniques (camera, lidar), capacitive sensing, microwave (RFID, WIFI, ultrasound), inertial sensors dead reckoning (gyroscope and accelerometer). However, different sensors have their own unavoidable advantages and limitations. This thesis will focus on capacitive sensors to reveal their long-range front-end characteristics. The reason for choosing a capacitive sensor is its low cost, low power consumption, and effective sensing. And currently, more research is focused on short-distance applications of capacitive sensors.