Abstract: Safe and stable supply of uranium resources is of great significance for ensuring national security and promoting the sustainable and healthy development of the nuclear industry. Aiming at the technical bottleneck of the high-efficiency mining of low-permeability sandstone-type uranium deposits in our country， a technical idea of a low-permeability sandstone-type uranium deposit with liquid CO2 phase transition fracturing and high-efficiency mining method was proposed. That is， the liquid CO2 phase transition fracturing technology was used to generate a large number of interconnected fracture between the in-situ leaching extraction holes and injection holes to improve the seepage capacity of the low-permeability uranium ore. The theoretical method was used to calculate the influence radius of liquid CO2 phase transition fracturing， and the liquid CO2 phase transition fracturing and permeability enhancement in-situ leaching mining process was established. The system carried out a feasibility study on low-permeability sandstone-type uranium deposits with liquid CO2 phase transition fracturing to increase permeability and high-efficiency mining. The results showed that: The influence radius of liquid CO2 phase change fracturing to increase permeability technology was 6.53 m. This technology can achieve rock fracture failure under three-dimensional stress conditions， could effectively increase the distribution of rock damage and fracture network， and has the advantages of rock fracturing， reducing chemical precipitation and economic feasibility. The results of this paper provided a possible way to solve the problem of low permeability and low leaching rate in the process of in-situ leaching of sandstone-type uranium deposits， and would be of great significance to the future breakthrough of the low-permeability sandstone uranium ore problem with low leaching rate.

Key words: low permeability, sandstone type uranium deposit, in-situ leaching mining, carbon dioxide fracturing, rock failure