Deep blind hole inner diameter automatic measuring device and measuring method

The invention discloses a deep blind hole inner diameter automatic measuring device and measuring method. The deep blind hole inner diameter automatic measuring device comprises a front measuring module, a middle stop module and a rear driving module. The front measuring module is connected with the rear driving module through the middle stop module. Firstly the front measuring module, the middlestop module and the rear driving module are placed in the deep blind hole to be measured from the inside to the outside in turn during measurement; secondly, the rear driving module pushes the front measuring module and the middle stop module to move in the deep blind hole, and the front measuring module completes the measurement of the inner diameter of the deep blind hole; and finally the middlestop module automatically stops the measuring device at the bottom end of the deep blind hole, and the rear driving module drives the front measuring module and the middle stop module to reversely move to the orifice. The non