The present invention provides a high-voltage isolating device (1), including a power module (11) and a shelf (12). The power module's back panel is provided with a first connecting portion (112), and the power module's front panel is provided with a first fastening member (113). The shelf includes a module slot (121) for accommodating the power module. The module slot's rear end is provided with a second connecting portion (122), and the module slot's front end is provided with a second fastening member (123). Wherein in a first status, the first connecting portion is matched and connected with the second connecting portion, and the first fastening member is away from the second fastening member; and in a second status, the first connecting portion is disconnected from the second connecting portion, and the first fastening member and the second fastening member are matched and connected together by a padlock.