The invention belongs to the field of electric system reactive power compensation, and provides a combination switch type step controllable shunt reactor. The controllable shunt reactor body adopts a transformer structure and can be designed into two forms based on requirements, i.e. the high short circuit impedance form or the form of an ordinary transformer with an external reactor. In the controllable shut reactor, combination switches are controlled to be matched with body short circuit impedance, thus the output of reactive capacity and the step regulation can be realized; each combination switch includes a circuit breaker, a thyristor valve, and a reactor, wherein the circuit breaker is connected in series with the reactor; when the controllable shunt reactor operates stably at a capacity step, the circuit breakers are closed to bear long-term working current, and the thyristor valves do not need work for a long time; and during step regulation of capacity, the to-be-taken energy and the turning-on voltage are provided for the thyristor valves based on the divided voltage provided by the reactor connected with the circuit breaker in series, so that current can be connected and disconnected in a zero-crossing switching manner by the thyristor valves without switching on/off the circuit breakers, so that the service life of the circuit breaker is prolonged.