The invention relates to a reactive equipment operation state checking method in automatic voltage control of a transformer substation and belongs to the technical field of electric power system automatic voltage control. The method comprises the steps of: firstly according to a topological structure of a current power grid, forming a control unit of the transformer substation; secondly, checking the operation state of reactive equipment according to reactive equipment measured data in the control unit; checking consistency between remote measuring and remote signaling of a capacitor and a reactor on a low voltage side of a main transformer firstly; then checking consistency between reactive remote measuring of the capacitor and the reactor on the low voltage side of the main transformer and reactive remote measuring of the low voltage side of the main transformer; and if the checking is not passed, automatically locking the automatic voltage control of the transformer substation. By adopting the method, the operation state of transformer substation reactive equipment in the automatic voltage control is rapidly and accurately checked, false control caused by inaccurate measuring is avoided, and the safe operation requirements of the transformer substation equipment are met.