The invention relates to a multifunctional automatic measuring instrument of a large-scale precise bearing axial play, which comprises an electric system (1), a precise pressure gauge (2), an upper pressing sleeve (3), a precise pressure regulating valve (5), a sensor regulating stand (6), a lateral inductance transducer (7), a gauging mandrel (8), a lower pressing sleeve (9), a gauging main spindle and a charger (10), a bearer (11), a fork-lever coupling (12), a Hall component (13), a synchronous motor (14), and a gauging base (15). The invention solves the difficult problem that a large-scale precise bearing axial play is hard for highly precise measurement, a reliable detecting and analyzing data is provided for assembling and employing a bearing, and a measured bearing (4) is multifunctionally and automatically measured, a need of quick test for a bearing user is satisfied, simultaneously, a measuring standard of an axial play is provided for a precise bearing of a non-separable large-scale finished product which is larger than 100mm.