The invention discloses a triggering device and a triggering control method for a thyristor valve block of a high-voltage TSC (thyristor switched capacitor), and belongs to the field of electric system controllers. With the triggering device and the triggering control method, the problems of complex structures of existing triggering devices and complexity of existing triggering control methods are solved. A control unit is connected with the triggering device. The triggering control method includes that an external clock circuit is adopted to provide clock signals to a logical processing unit, collected SIN signals are judged to acquire switching time, switching signals are outputted according to the switching time, and the switching signals are converted to optical signals through a light transmission circuit to be outputted to a light receiving circuit after being amplified by a driving circuit; and the light receiving circuit outputs electric pulse signals to an optical-coupling isolation circuit II, and input sides of two optical-coupling isolation circuits are switched on simultaneously when the electric pulse signals are of low levels, so that two triggering signals are outputted by two triggering units to gate poles of the thyristor valve block of the high-voltage TSC simultaneously. The triggering device and the triggering control method are applicable to electric systems and industrial systems.