Carbon dioxide fracturing medium phase change control system and method

The invention provides a carbon dioxide fracturing medium phase change control system and method.A liquid carbon dioxide storage tank is connected with an inlet of a booster pump device through a manifold, an outlet of the booster pump device is connected with an inlet of a fracturing pump device, an outlet of the fracturing pump device is connected with a circulation switch set, and the circulation switch set is provided with two outlets; one outlet of the circulating switch group is connected with a wellhead, and the other outlet of the circulating switch group is connected with the booster pump device; a speed adjusting device is arranged on the fracturing pump device and used for adjusting the output flow of the fracturing pump device. The pressurizing pump device and the fracturing pump device can be cooled through liquid carbon dioxide before operation, gas in the system is reduced through pressure control in the circulation process, and the situation that the size is increased due to gasification of th