Method for controlling of cooling system for HEV vehicle

A method of controlling a cooling system for a hybrid electric vehicle, the method comprising:

• measuring an outside air temperature through an outside air temperature measurement unit;
• determining whether the measured outside air temperature is within a preset low-temperature environment temperature range;
• in a case where the outside air temperature is within the preset low-temperature environment temperature range, determining whether a vehicle state detected by a vehicle state determination unit corresponds to a preset heating mode;
• in a case where the vehicle state does not correspond to the preset heating mode, detecting a coolant temperature through a coolant temperature measurement unit;
• and
• in a case where the coolant temperature detected by the coolant temperature measurement unit is within a preset target temperature range, controlling opening and closing of a control valve to selectively perform a coolant flow stop control in a low-temperature environment.