A power unit according to an exemplary embodiment of the present disclosure may include: a power module which is configured by a power conversion switching element, the power module having a first side having gate pins connected to a board, and a second side to which main busbars are connected; cooling modules which are disposed on both surfaces of the power module, respectively; capacitor modules which are disposed on outer surfaces of the cooling modules, respectively, and have capacitors that are electrically connected to the main busbars through connecting busbars, respectively; a coolant supply pipe which is connected to one end portion of each of the cooling modules to supply a coolant to the cooling module; and a coolant discharge pipe which is connected to another end portion of each of the cooling modules to discharge a coolant discharged from the cooling module.