A bypass seamless switching apparatus and a method thereof are provided, in which a controller sends a first control signal to control or switch a first relay to on/off state, sends a second control signal to control or switch a second relay to on/off state, and sends a switch signal to control or switch a bypass switch module to on/off state. When the controller is in failure mode or is disconnected, a driving power supply of a bypass circuit provides a driving signal to the bypass switch module to maintain or switch a switch of the bypass switch module to on state, so that the bypass switch module is in short-circuit state or short-circuit protection state, and a bypass side voltage of the bypass switch module is equal to or close to zero voltage, so as to execute bypass function or bypass seamless switching function of the bypass switch module.