An apparatus for driving a thyristor in an alternating-current power grid includes a non-isolated power supply circuit and a throttling circuit. One terminal of a power supply input of the non-isolated power supply circuit is connected to a first terminal of the thyristor. The other terminal of the power supply input is connected to another phase of the power supply relative to the first terminal or a neutral lead. The non-isolated power supply circuit forms a signal trigger loop through the throttling circuit, a second terminal of the thyristor and the first terminal of the thyristor. A control terminal of the throttling circuit is connected to a third terminal of the thyristor. The apparatus of the present invention has advantages of occupying a small space and having a simple circuit, a great instantaneous triggering current, a high cost effectiveness, and a low power consumption.