The invention discloses a state indicating instrument of a three-working-position operating mechanism of a high-voltage switch cabinet and a state indicating method thereof. The indicating instrument comprises a grounding switch displacement sensor, an isolating switch displacement sensor, a switching amount input circuit, a key circuit, a microprocessor, a grounding switch state indicating circuit, an isolating switch state indicating circuit, a grounding switch action counting circuit, an isolating switch action counting circuit, a switching amount output circuit, a power circuit and a working state indicating circuit, wherein the grounding switch displacement sensor, the isolating switch displacement sensor, the switching amount input circuit, the key circuit, the grounding switch state indicating circuit, the isolating switch state indicating circuit, the grounding switch action counting circuit, the isolating switch action counting circuit, the switching amount output circuit, the power circuit and the working state indicating circuit are respectively connected with the microprocessor. The state indicating instrument disclosed by the invention has the advantage that position information of an isolating switch and a grounding switch can be acquired in real time.