The invention discloses a design method for an air reactor used for an oscillatory wave system, comprising the following steps: firstly, acquiring wire parameters and an inductance parameter of a reactor; secondly, calculating self inductance of each turn of coil in the reactor and mutual inductance among coils; thirdly, calculating the total inductance W of the reactor, wherein the total inductance W includes the sum total of the self inductances of the coils and the sum total of the mutual inductance among the coils; fourthly, calculating the total winding length L, the total winding weightG and the total resistance value R of the coils in the reactor; and fifthly, changing partial initialization values of wire parameters and the inductance parameter of the reactor, thus the designed reactor has a specific total inductance, a specific total resistance value, a specific total winding weight and a specific total winding length. The design method disclosed by the invention has good universality, the reactor with a relatively high total inductance and a relatively low total resistance value can be conveniently designed by changing the initialization values of the wire parameters andthe inductance parameter of the reactor, and reliability and accuracy of cable partial discharge detection can be beneficially improved.