The phase-controlled arc-suppressing coil is a type of adjustable arc-suppressing coil controlled by TCR（Thyristor Controlled Reactor）， being capable of the large adjustable range of current and the continuously adjusted compensation current. In this paper， the working characteristics of arc-suppressing coil controlled by TCR are demonstrated and the correctness of theoretical analysis is proved by the related simulation with ATP（Alternative Transient Process） and experiments on the simulated 10 kV power distribution network. It is indicated that the distortion ratio of harmonic currents can be controlled within the finite range by the filtering circuit， which， however， slowers the response speed of the circuit and produces the cross-zero disorder. The correspondent controlling strategy has been designed through an analysis of some key problems in controlling， greatly improving the compensation effect and operating safety.