High performance liquid chromatography protection column sleeve

The utility model discloses a high performance liquid chromatography protection column sleeve which comprises a column casing, a central column is inserted on the end face of one side of the column casing, a column core and a plug are arranged in the central column, and the plug is detachably connected at the position of a port of the central column to prevent the column core from falling off. A plurality of through holes are formed in the outer wall of one end, far away from the plug, of the central column, a separation ring is fixedly connected to the bottom wall of the column casing, the separation ring is arranged on the outer side of the central column in a sleeving manner, and the separation ring and the through holes are arranged in a staggered manner. The liquid flows to the through hole through the annular gap between the column casing and the separation ring, then passes through the column core and the filter plate through the through hole, and is discharged from the connecting pipe, the column core