A simulation model of microwave photonic filters (MPF) based on Brillouin Raman fiber laser (BRFL) is demonstrated. A wide tunability filter in terms of its bandwidth and free spectra range is achievable by controlling BRFL optical channel numbers and wavelength spacing thanks to the high optical channels count offered by the BRFL. Characteristics of MPF based on the BRFL parameters were investigated and reported. This model serves as the reference for practical MPF design using multiwavelength BRFL. A high selectivity filter could be achievable with 38.1 MHz 3 dB bandwidth.