The invention provides a supporting type overhead tube bus displacement monitoring device and a monitoring system. A laser infrared distance measurement sensor is installed on a metal support under a tube bus, an oblique-plane reflection plate is installed at the end of the tube bus position, infrared laser is transmitted to a reflector through the laser infrared distance measurement sensor to measure a distance between the end of the tube bus and a laser head, and the tube bus horizontal displacement amount is measured through calculation. The supporting type overhead tube bus displacement monitoring device comprises a master control, a processing unit module, a minor control, a processing unit module, a laser distance measurement module, a temperature and humidity measurement module and an industrial personal computer. The supporting type overhead tube bus displacement online monitoring system can check thermal-stretching cold-contraction change data and a curve of a tube bus within a time period on the ground in real time, establish a mathematic model, perform pre-warning on stuck phenomena occurred between the bus and a wire clamp and between an expansion joint and the wire clamp due to thermal stretching and cold contraction of the tube bus and detect whether the tube bus can freely perform thermal stretching and cold contraction on the wire clamp or not.