An integrated device for inspecting ground faults of a direct-current system belongs to the field of electrical measurement and comprises a current sensor arranged on a direct-current system output circuit. The integrated device is characterized in that the device is provided with an active LC oscillator, an impulse counter, a microprocessor circuit, a trigger, an alarm circuit and a power supply generation circuit that are sequentially connected; the above circuits are integrated inside a casing, and a direct-current system output circuit connecting terminal is arranged at one end of the casing; a direct-current system load circuit connecting terminal is arranged at the other end of the casing; an alarm circuit lightening hole is arranged on one surface of the casing; and a fixing clip/hook connected with a terminal block of a control cabinet is arranged on the other surface of the casing. The device can monitor the ground faults of the direct-current system by measuring oscillation frequency variation of the active oscillator arising from the difference circuit generated when the direct-current system is grounded, and directly sends an alarm signal. The device overcomes the shortcomings of the prior art, better ensures the normal operation of the original system, can realize distributed installation, and can conveniently realize real-time on-line monitoring.