The invention discloses a safety detecting method and device of authentication liquid. The method includes the following steps: a, scanning the barcode of a vessel filled with to-be-detected liquid and searching out the corresponding information of the barcode in a database; b, placing the vessel filled with the to-be-detected liquid on the platform of a CT device; c, adopting dual-energy Gamma-ray to obtain the projection data of the to-be-detected liquid, so as to obtain CT image and liquid and vessel information; and d, comparing the information of the step a with that of the step c. The method has higher detection accuracy, and the device is rather convenient to operate.