The invention relates to an adjusting device capable of changing a chromatographic peak type of a liquid chromatogram. The adjusting device can be taken as an individual member of a chromatographic column. The chromatographic peak type adjusting device is mounted at the upper part of a sieve plate at the outlet end of the chromatographic column or at the lower part of a sieve plate at the inlet end, and a circular convex body structure extends to the middle of a chromatographic column medium. The chromatographic peak type adjusting device is divided into two parts: a circular base and the circular convex body structure, and the diameter of the circular base can be designed according to the internal diameter of the chromatographic column. A member at the central part of the chromatographic peak type adjusting device is of the impermeable circular convex body structure and is smooth in surface and bilaterally-symmetrical; the proportion of the diameter of the bottom surface of a circular convex body at the central solid part to the internal diameter of the chromatographic column is 0.1-0.9, and the proportion of the height of the circular convex body to the column length of the chromatographic column is 0.01-0.30. The periphery of the circular convex body is of a permeable porous mesh-shaped structure, and the circular base and the circular convex body structure can be combined into a whole body. Materials for the device include, but are not limited to stainless steels, organic glass, Teflon and other materials without specific adsorption.