Measuring equipment and method for measuring size of shell

The invention relates to measuring equipment and method for measuring the size of a shell. The measuring equipment comprises a positioning base, a guide device, a support, a linear driving mechanism for driving the support to move left and right, and a first hole center measuring unit installed on the support. A shell positioning plane is arranged on the positioning base, a plane which vertically penetrates through the center of the shell positioning plane and extends in the left-right direction is a guide reference plane, the positioning base is used for installing the shell, the shell positioning plane is in contact and attached to the end face of the shell, and the positioning base is further provided with a positioning mechanism. The guide device is used for enabling the axis of the first inner hole to be located on the guide datum plane. The first hole center measuring unit comprises an upper lever and a lower lever which are symmetrically arranged, a displacement detection assembly and a rotation drivin