Lock mechanism with state indication function

A lock mechanism with state indication function includes a housing, a cap and an indicator. The indicator includes active and passive indicators arranged circumferentially around a central axis. The active indicator includes a cam matching surface extending circumferentially around the central axis and a stopping end located at an end of the cam matching surface corresponding to the pivoting center of the active indicator. The radial convex portion slides along the cam matching surface to make the active indicator rotate away from the central axis. The radial convex portion pushes the stopping end of the active indicator to make the active indicator rotate to a recovery position in which the indicating portion is covered by the cap. The passive indicator is in linkage connection with the active indicator through a gear transmission device, making the passive indicator be unfolded and folded synchronously along with the active indicator.