A unitary air conditioning unit for a railway train, comprising: a fixed frame , a compressor , an evaporator (3-1), and a condenser (3-2) 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 (5-2), and, a high-pressure fan (6-1), a heater , an evaporating fan (6-2) and a condenser fan (6-3) are further provided in the fixed frame , the high-pressure fan (6-1) has an air inlet towards the air vent B (5-2) and an air outlet opening into an evaporation chamber, the evaporating fan (6-2) 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 (6-2) 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 (5-1), the air vent A (5-1) and the air vent B (5-2) are located above the condensation chamber, and the condenser (3-2), the condenser fan (6-3), the compressor and the high-pressure fan (6-1) are provided in the condensation chamber, and the evaporating fan (6-2), the heater and the evaporator (3-1) are provided in the evaporation chamber. a fixed frame , a compressor , an evaporator (3-1), and a condenser (3-2) 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 (5-2), and, a high-pressure fan (6-1), a heater , an evaporating fan (6-2) and a condenser fan (6-3) are further provided in the fixed frame , the high-pressure fan (6-1) has an air inlet towards the air vent B (5-2) and an air outlet opening into an evaporation chamber, the evaporating fan (6-2) 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 (6-2) 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 (5-1), the air vent A (5-1) and the air vent B (5-2) are located above the condensation chamber, and the condenser (3-2), the condenser fan (6-3), the compressor and the high-pressure fan (6-1) are provided in the condensation chamber, and the evaporating fan (6-2), the heater and the evaporator (3-1) are provided in the evaporation chamber. <EOS>