A unitary air conditioning unit for a railway train, comprising: a fixed frame, a compressor, an evaporator, and a condenser mounted in the fixed frame and communicated with a refrigerant pipeline, wherein a cover plate is mounted on the fixed frame, the cover plate is provided with an air vent B, and, a high-pressure fan, a heater, an evaporating fan and a condenser fan are further provided in the fixed frame, the high-pressure fan has an air inlet towards the air vent B and an air outlet opening into an evaporation chamber, the evaporating fan has an inlet provided in the evaporation chamber and an outlet communicated with an air duct, the air duct is provided for delivering air into a car, and the evaporating fan is provided for delivering air in the evaporation chamber to the air duct, wherein the fixed frame is a rectangular frame, and four vertical protective plates are sequentially provided under edges of the rectangular frame to surround the rectangular frame, and the unitary air conditioning unit further comprises a bottom plate provided under the protective plates, wherein a vertical middle partition plate is provided in the rectangular frame, the evaporation chamber and a condensation chamber are formed at two sides of the middle partition plate, the evaporation chamber and the condensation chamber are independent of each other and isolated from each other through the middle partition plate in a sealed manner, the cover plate is further provided with an air vent A, the air vent A and the air vent B are located above the condensation chamber, and the condenser, the condenser fan, the compressor and the high-pressure fan are provided in the condensation chamber, and the evaporating fan, the heater and the evaporator are provided in the evaporation chamber. a fixed frame, a compressor, an evaporator, and a condenser mounted in the fixed frame and communicated with a refrigerant pipeline, wherein a cover plate is mounted on the fixed frame, the cover plate is provided with an air vent B, and, a high-pressure fan, a heater, an evaporating fan and a condenser fan are further provided in the fixed frame, the high-pressure fan has an air inlet towards the air vent B and an air outlet opening into an evaporation chamber, the evaporating fan has an inlet provided in the evaporation chamber and an outlet communicated with an air duct, the air duct is provided for delivering air into a car, and the evaporating fan is provided for delivering air in the evaporation chamber to the air duct, wherein the fixed frame is a rectangular frame, and four vertical protective plates are sequentially provided under edges of the rectangular frame to surround the rectangular frame, and the unitary air conditioning unit further comprises a bottom plate provided under the protective plates, wherein a vertical middle partition plate is provided in the rectangular frame, the evaporation chamber and a condensation chamber are formed at two sides of the middle partition plate, the evaporation chamber and the condensation chamber are independent of each other and isolated from each other through the middle partition plate in a sealed manner, the cover plate is further provided with an air vent A, the air vent A and the air vent B are located above the condensation chamber, and the condenser, the condenser fan, the compressor and the high-pressure fan are provided in the condensation chamber, and the evaporating fan, the heater and the evaporator are provided in the evaporation chamber.