The invention discloses a superconductive controllable reactor, which comprises a first segmented magnetic yoke, a second segmented magnetic yoke, a working coil, a superconductive excitation coil group and a low-temperature dewar, wherein the first segmented magnetic yoke is an iron core; the second segmented magnetic yoke comprises an excitation iron core group and two same cambered iron cores; the excitation iron core group consists of a plurality of excitation iron cores which are distributed and clamped in the two cambered iron cores of the second segmented magnetic yoke at equal radians; each excitation iron core is sleeved on each superconductive excitation coil; the inductance values of the superconductive excitation coils are the same, and the superconductive excitation coil group is formed by connecting the superconductive excitation coils in series; the two adjacent superconductive excitation coils are sequentially connected with one another according to homonymy terminals and synonym terminals; the number of the superconductive excitation coils and the number of the excitation iron cores are the same and even; and the superconductive excitation coils and the excitation iron cores are arranged in the non-magnetic low-temperature dewar. The superconductive controllable reactor can continuously and adjustably compensate the reactive power of a power grid in a large scale, so that reactive power balance is realized, the stability of a power transmission system is improved, the power transmission capacity is improved, and system overvoltage is suppressed.