Provided is a cooling and heating system for a vehicle, in which a compressor, an indoor condenser, an outdoor condenser, and an evaporator are connected to a refrigerant circulation line in which a refrigerant is circulating, the cooling and heating system including: a waste heat chiller connected to the compressor through a first bypass line in the refrigerant circulation line; a battery chiller connected to the compressor through a second bypass line in the refrigerant circulation line; a first coolant line circulating a coolant by connecting the waste heat chiller to an electric radiator and an electric unit arranged adjacent to the outdoor condenser; a second coolant line spaced apart from the first coolant line and circulating the coolant by connecting the battery chiller to a battery of the vehicle; and a coolant control unit connecting the first coolant line and the second coolant line.