The in-situ test of compressed air energy storage (CAES) is a key link to verify the performance of underground air storage under real geological conditions

and its scale design is directly related to the representativeness of test results and construction cost.Aiming at the key control geometric parameters of the buried depth

tunnel diameter and tunnel length of the test storage cavern

the design method of tunnel buried depth and tunnel diameter is studied by using limit equilibrium method and numerical simulation method.The design method of cavern length is put forward from the point of thermodynamics.The rationality of the proposed design method is verified by an engineering case.The results show that the buried depth of the cavern has a significant influence on the stability of surrounding rock

and the buried depth of the test library should reduce the construction cost as much as possible on the premise of meeting the requirements of safety and stability.Under different hole diameters

the distribution of stress and deformation around the hole is similar

and a smaller cavern diameter can meet the simulation requirements of test conditions.The length of the cavern has a significant influence on the thermodynamic response characteristics of storage cavern.If the cavern is too short

the temperature inhomogeneity will be difficult to reflect

and if it is too long

the construction cost will be greatly increased.