The invention relates to a narrow band thin-layer chromatographic sheet which comprises a base plate. A straight groove is arranged on the chromatograph base plate, a fixed phase is precipitated in the straight groove, and fixed phase substances are selected from silver iodide, barium fluoride, calcium fluoride, silver bromide or zinc sulfide. The fixed phase of the chromatographic sheet is small in consumption, the cost is low, the detection sensitivity is high, the plating time is short, and the usage is convenient.