Rock core holder capable of being adjusted and rapidly replaced

The invention discloses an adjustable quick-change rock core holder which comprises a fixed plate and a movable plate, the fixed plate and the movable plate are connected through an adjusting assembly, a plurality of clamping assemblies are arranged on the fixed plate and the movable plate, each clamping assembly comprises a fixed cylinder and a movable cylinder, a first plug, a second plug, a rubber cylinder and a first ejector rod are arranged in each fixed cylinder, and a second plug, a rubber cylinder and a second ejector rod are arranged in each movable cylinder. According to the device, the movable plate is moved through the adjusting assembly, the fixed barrel is opened, so that the first plug, the second plug and the rubber barrel are installed on the fixed barrel, the fixed barrel and the movable barrel are mutually fixed through the movable assembly, and the position of the second plug is adjusted through the pushing assembly, so that the device is suitable for cylindrical rock cores with different