The present invention provides a detection method of parecoxib sodium genotoxicity impurity and application thereof. The method uses a reversed-phase liquid chromatography method. The chromatography conditions are as follows: the chromatographic column comprise a C18 column, a C8 column, a phenyl column and a Hilic column; a mobile phase consists of water-acetonitrile, dilute phosphoric acid-acetonitrile, and phosphate-acetonitrile; a flow phase comprises an aqueous phase and an organic phase in the ratio of 90:10-10:90; the column temperature is 25-40 DEG C; the flow rate of the mobile phase is 0.2-2ml / min; detection wavelength is 205-290nm; a detector is a UV detector or a photodiode array (PDA) detector; and the sample size is 0.1-40 mul. The detection method of parecoxib sodium genotoxicity impurity achieves the separation of parecoxib sodium and three genotoxicity impurities in a short period of time, has high sensitivity and specificity, and simple operation, reaches the separation rate of the main component and genotoxicity impurities, and the separation rate of genotoxicity impurities both greater than 1.5; and the method can be used for quality control of parecoxib sodium, and has practical value.