In-box spacing measuring device and method

The invention discloses an in-box spacing measuring device and an in-box spacing measuring method. The in-box spacing measuring device comprises a measuring body, a reference end, and a measuring end. There is a first distance between the reference end and the measuring end in a first direction. A measuring member used for displaying the result of measurement is movably assembled on the measuring body along the first direction, and the measuring end is arranged on the measuring member. A reference member is movably assembled on a second end along the first direction, and the reference end is arranged on the reference member. The reference member moves along the first direction, and thus has a reference state and an avoiding state. The reference end extends out of the second end in the reference state. The measuring member moves along the first direction, and thus has a moving state, a first locked state and a second locked state. The measuring body is equipped with a reference locking member used for locking the reference member in the reference state and a measurement locking member used for locking the measuring member in the first and second locking states. The technical problem in the prior art that the surface of a measured component may be scratched as a measuring gauge cannot retract in reading is solved.