The invention relates to a method for monitoring overhead tube bus displacement and provides a supporting type overhead tube bus displacement monitoring device and a monitoring method. Infrared laser is transmitted to a reflector through a laser infrared distance measurement sensor, a distance between a tube bus end and a laser head is measured, and the tube bus horizontal displacement amount is measured through calculation. A calculation formula is (shown in description). The supporting type overhead tube bus displacement online monitoring method 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.