Express size measuring device and method

The invention discloses an express size measuring device and method, and solves the problem that the size of a logistics item is difficult to measure quickly in the prior art. The express size measuring device is characterized by comprising an objective table, wherein a fixed vertical rod is arranged at the side part of the objective table, a protective shell is arranged at the top part of the fixed vertical rod, a camera and a laser device are arranged in the protective shell, and the laser device emits a red laser surface, a green laser surface and a blue laser surface; the red laser surface and the green laser surface do not intersect after being emitted by the laser device, an angle theta 0 formed between the red laser surface and the green laser surface ranges from 15 degrees to 30 degrees, and the blue laser surface intersects with the red laser surface and the green laser surface after being emitted by the laser device. The express size measuring device is used in cooperation with the express size meas