A bandwidth-reconfigurable filter is necessary to meet the need of growing communication capacity and signal cover-age frequency range. The stimulated Brillouin scattering (SBS) gain spectrum as a filter passband is used to extract de-sired microwave signals. Due to the fact that the passband is formed by mapping the Brillouin gain spectrum, band-width reconfigurability can be implemented by changing Brillouin gain linewidth. In this paper, a scheme using a 5-lines optical comb acting as a Brillouin pump is experimentally demonstrated. The spectrum of the 5-lines optical comb is extended by a binary phase shift keying (BPSK) pulse modulated signal. Experiments have shown that the 3-dB and 20-dB bandwidths of the filter are 196 MHz and 257 MHz, respectively, and its 20-dB shape factor is 1.31. The passband ripple is ~3.5 dBm with stop-band rejection of 20 dBm under 15 dBm optical pump power.