The utility model discloses a metro track measuring device, which relates to the technical field of measuring tools, and comprises a first non-zero track change device and a second non-zero track change device, the first non-zero track change device is arranged on a first side track, and the second non-zero track change device is arranged on a second side track; the zero-finding
reference surface extension block is placed on the first non-zero rail zero-finding device and the second non-zero rail zero-finding device, the first gradienter is arranged at one end of the zero-finding
reference surface extension block, the first gradienter is connected with a
laser range finder, and the
laser range finder is used for measuring and displaying data. According to the invention, the numerical error generated by the non-zero rail to the measured floor surface can be effectively eliminated, and the method can be applied to most operation projects requiring the zero rail
reference surface, thereby reducing the unreliable factors of different measurement personnel, improving the measurement accuracy, improving the working efficiency to a great extent, and shortening the overall
operation time.