Hybrid electric vehicle, HCU and idle speed control method of hybrid electric vehicle

The invention provides a hybrid electric vehicle, an HCU and an idle speed control method of the hybrid electric vehicle. The method includes the steps that whether the vehicle has a torque requirement or not is judged; when it is confirmed that the vehicle does not have the torque requirement, charging information of a high-voltage battery is received from a high-voltage battery controller; the water temperature and air conditioning state of an engine are detected; according to the charging information of the high-voltage batter and the water temperature and air conditioning state of the engine, a first idle speed target value of the engine is calculated; the first idle speed target value of the engine is sent to an engine controller, so that the engine controller correspondingly adjusts the rotation speed of the engine according to the first idle speed target value of the engine. By means of the scheme, the idle speed control of the hybrid electric vehicle can be achieved.