The invention discloses a device suitable for a compression mechanical performance test and a bending mechanical performance test under high-temperature vacuum environment. The device comprises a high-temperature vacuum box, wherein an upper pressing rod connected with an upper chuck is arranged in the high-temperature vacuum box; a lower chuck assembly and a drive mechanism are also arranged in the high-temperature vacuum box, wherein the lower chuck assembly comprises a tray and a plurality of lower chucks which are arranged on the tray, and the lower chucks are used for fixing a specimen; the drive mechanism is connected with the tray, is used for shifting different lower chucks, and is located right above a lower pressing rod; the lower pressing rod can drive the lower chuck right above the lower pressing rod to move in the compression direction of the specimen and/or the upper pressing rod can drive the upper chuck to move in the compression direction of the specimen. Through the adoption of the device, the test efficiency is greatly improved.