The invention discloses a measure ruler special for animal shape size measurement. The measure ruler comprises a graduation ruler and an elastic device used for enabling the graduation ruler to be contracted backwards, the elastic device is mounted on a shell, a ruler head is arranged at one end of the graduation ruler, a connecting segment for connecting the elastic device is arranged at the other end of the graduation ruler, a laser transmitter is arranged on the surface, above the graduation ruler, inside the shell, a laser receiver is arranged at the position, below the graduation ruler, of the shell, a touch button is arranged on the shell, a displayer is arranged on the outer surface of the shell, a sensor used for monitoring the moving direction of the graduation ruler is arranged inside the shell, and the laser transmitter, the laser receiver, the touch button and the sensor are connected to a controller. The size of the graduation ruler can be efficiently and precisely determined in a laser counting mode, and meanwhile the ruler needs to solve the problem that in the data measuring process, due to the measurement requirement, sometimes, the graduation ruler is contracted inwards, and the backward counting of the graduation ruler is required.