The invention discloses a heparin detection method. Perylene-3,4,9,10-tetracarboxylic acid dianhydride and sodium hydroxide are synthesized under certain conditions to generate perylene-3,4,9,10-tetracarboxylic acid (PTCA), PTCA can be combined with cetyl trimethyl ammonium bromide (CTAB) to generate a PTCA/CTAB compound; as the CTAB concentration increases, the fluorescent strength of the system increases; and when heparin is added into the system, because heparin can capture CTAB from the PTCA/CTAB compound to form a stable heparin/CTAB compound, the fluorescence of PTCA is recovered. The heparin concentration is taken as the X axis, corresponding fluorescence quenching ratio is taken as the Y axis, a linear equation of heparin concentration and fluorescence quenching ratio can be obtained namely F=-26.0 C+551.58, the linearly dependent coefficient R2 is 0.9895, and according to the linear equation and fluorescence quenching ratio after adding heparin into a solution to be detected, the heparin concentration of the solution can be determined.