Thyristor-controlled LC-coupling hybrid active power filter (TCLC-HAPF) is characterized with low DC-link voltage and wide operational range, which was recently developed for power quality conditioning in the medium-voltage-level system. This paper proposes a fuzzy logic based adaptive source current total harmonic distortion (THD) controller for the TCLC-HAPF. The proposed controller can adaptively change the hysteresis band (HB) according to the reference THD value, thereby possibly reduce the switching loss and keep the source current THD at an acceptable reference level. Simulation is conducted for verifying the proposed controller, in comparison with the fixed HB controller.