The invention discloses a compact thyristor trigger protection unit, which is a core component of a high power rectifier and an inverter bridge. The thyristor trigger protection unit disclosed by the invention comprises a cover plate, a heat radiator, a shell, a capacitor, a resistor and a thyristor trigger module, wherein the capacitor, the resistor and the thyristor trigger module are all placed inside the sealed metal shell; the metal shell is good in electromagnetic shielding performance and strong in signal anti-interference ability; the heat radiator is connected with the shell in a fixed mode; the thyristor trigger module and the resistor are located in the cavity of the shell and fixed on the surface of the heat radiator; and the heat radiator diffuses heat generated when the thyristor trigger module and the resistor work. The thyristor trigger protection unit is strong in signal anti-interference ability, stable in operation, compact in structure and convenient in installation.