Inner spherical surface size rapid measuring device

The invention discloses an inner spherical surface size rapid measuring device, which comprises a shell (5), a positioning assembly, a sliding assembly and a measuring assembly. the positioning assembly is arranged on the outer wall of the shell (5); the sliding assembly is arranged in the cavity of the shell (5) and can move up and down along the cavity of the shell (5); AND the measuring assembly is arranged at the top of the shell (5) and connected with the sliding assembly, and the measuring assembly is driven by the sliding assembly to measure the size of the inner spherical surface (9). According to the invention, the center of the inner spherical surface (9) can be quickly and accurately positioned, the size of the inner spherical surface (9) can be accurately measured through calculation after data is read by the dial indicator (4), and the detection precision of the engine part (8) can be improved, so that the qualified rate of the engine part (8) is ensured; usage is convenient, random movement can