The utility model relates to the technical field of CO2 oil displacement and ground storage processes in an oil field, and in particular relates to pressurized unloading and storage in a storage tank after liquid-state CO2 is transported to a target site by virtue of a tank car. A pressurized acceleration type CO2 tank car unloading system comprises a liquid-state CO2 tank car, wherein a liquid-state CO2 storage tank is arranged in the tank car. The pressurized acceleration type CO2 tank car unloading system is characterized in that the liquid-state CO2 storage tank is provided with a liquid-phase output pipeline and a gas-phase input pipeline, wherein the liquid-phase output pipeline is divided into a left pipeline and a right pipeline, and the left pipeline is connected with the CO2 storage tank while the right pipeline is connected with an inlet of a water bath type heater; and an outlet of the water bath type heater is connected with the gas-phase input pipeline. According to the pressurized acceleration type CO2 tank car unloading system provided by the utility model, the defects of long time consumption and incomplete unloading of a storage tank of an existing CO2 tank car in an unloading process are overcome; and the pressure of the storage tank of the CO2 tank car is boosted by virtue of water bath heating, so that the CO2 tank car has high working efficiency when used, and is clean and environmentally friendly and can work sustainably.