The invention discloses a heating device of a refrigerator door foaming fixture. The heating device comprises a device main body; each of two ends of the device main body is provided with a connecting end plate; each of two ends of an inner cavity of the device main body is provided with a protecting base plate; each of two ends of the device main body is provided with a temperature control device; the lower end of the temperature control device is provided with a clamping plate; an inner cavity of the temperature control device is provided with a regulating device; each of two sides of one end of the regulating device is provided with a connecting supporting rod; one end of the connecting supporting rod is provided with a fixed base plate; a driving rod is arranged between every two of the fixed base plates; the upper end of the driving rod is provided with a clamping supporting column, and one end of the clamping supporting column extends to the outer end of the temperature control device; and one end of the clamping supporting column is provided with a fixed end plate. The heating device has a favorable heating effect for the fixture and can have favorable use convenience in a using process, improve the using effect of the device, avoid bringing many unwanted troubles for a user and have a good using environment.