To realize the control of chaos in the voltage-mode BUCK converter, the output time-delayed feedback control (TDFC) is introduced into its control prototype. Based on the quantified analyses in the frequency domain, harmonic balance method is used to ascertain the regulating range of feedback control gain and delay time. Meanwhile the TDFC is equivalent to a kind of simple passive feedback control when the delay time is much smaller than the switch period. And the simulation results of these two methods are considered the same. In the end the experimental circuit of the voltage-mode BUCK converter with passive feedback control is set up. By this means the chaos state of BUCK converter can be quickly controlled into period state and the ripple of voltage and current will be decreased.