The invention discloses a transformer substation building settlement monitoring system based on a laser sensor. The system comprises a measuring device, an acquisition device, a network uploading device, a display device, an analysis system and an alarm system, wherein the measuring device is used for ceaselessly measuring the building displacement and transmitting measured data to the acquisitiondevice in real time, the acquisition device is used for uploading the acquired data to a server, the real-time data are displayed on the display device, the analysis system is used for analyzing datain the server according to the national settlement standard and outputting an alarming signal to the alarm system, and the alarm system gives a sound and light alarm. The online monitoring system isnot affected by weather, basically can ceaselessly perform measurement and analysis for a long time in various environments, realizes automatic and remote monitoring and masters the safety state of atransformer substation building in real time rapidly, effectively and accurately.