The invention discloses a hydraulic test device for a detachable housing of a combustion chamber case of an aeroengine. The test device comprises a pedestal, a base plate, an inner cylinder, a cover plate, an outer cylinder and a plug, wherein the base plate is arranged on the pedestal and connected with the lower end of the detachable housing of a part to be tested, the inner cylinder is placed at the inner lower end of the detachable housing and connected with the base plate and / or the pedestal, the cover plate is connected with the upper end of the inner cylinder, the outer cylinder is placed at the outer lower end of the inner cylinder and connected with the upper end of the detachable housing, the upper end of the outer cylinder is connected with the cover plate, and the plug is used to plug an opening in the detachable housing. The base plate, the inner cylinder, the cover plate, the outer cylinder and the detachable housing to be tested form a hydraulic annular enclosed space, and a part of the hydraulic annular enclosed space is provided with a hydraulic medium injection pipeline interface assembly, a hydraulic medium discharge pipeline interface assembly and an internal air discharge pipeline interface assembly of the annular enclosed space. The device can be used to detect the intensity, rigidity and welding compactness of the detachable housing, product is prevented from blindness, and guarantee is provided for producing combustion chamber cases, which satisfy using requirements, of the aeroengine.