The invention belongs to the technical field of three-dimensional detection of subway tunnels, and discloses a vehicle-mounted measurement device of three-dimensional deformation monitoring of subwaytunnels based on reference transmission. A rotatable laser distance measurement system for high-speed distance measurement and angle measurement is integrated by a laser range finder, an inclination angle sensor, a high-precision turn table and a PLC controller together; a tunnel section outline is measured in a discrete multi-point mode; meanwhile, in combination with a photoelectric encoder installed on a distance measurement wheel at the bottom of a tunnel detection vehicle, a fixed displacement amount of the detection vehicle between a starting position and a travelling position on an axial direction of the tunnel is obtained, a program is triggered, and the detected data of the specific position in the tunnel are transmitted to an upper computer by a wireless communicator. The vehicle-mounted measurement device disclosed by the invention makes breakthroughs in the practical technical innovation of the online monitoring of the tunnel structure safety, lays a foundation for forminga technical system for the reliability design, analysis, test and evaluation of rail transit facilities, and has practicality in many fields.