The invention provides a capacitor state detection method, which is characterized by at least comprising two coils, wherein the coils are arranged on two sides of a capacitor respectively, and the coils are coaxially arranged. The two coils are electrified and controlled to generate stable magnetic fields as well as an electric field between the two coils, magnetic flux penetrating the capacitor and a capacitance value between the two coils are detected, and the state of the capacitor is determined according to changes of the magnetic flux and the capacitance value. The capacitor state detection method and a capacitor state detection system provided by the invention can detect external state and internal state of the capacitor accurately, discover the state change of the capacitor timely and carry out corresponding processing on the changed capacitor, eliminate potential risks in a power grid, ensure power supply stability, reduce the use of manpower, reduce labor costs, and improve the detection efficiency and accuracy.