In this paper, we propose a broadband and frequency interval switchable multi-wavelength Brillouin random fiber laser. Due to the dual-open cavity configuration, the frequency interval of the output multi-wavelength laser can be switched between single and double Brillouin frequency shifts by adjusting the power ratio between the forward and backward BPs. The results show that when RP power is 831.8 mW, 253 Stokes lines with double Brillouin frequency shift interval (~0.176 nm) in a wavelength range of 44.5 nm (1528-1572.5 nm) and 483 Stokes lines with single Brillouin frequency shift interval (~0.088 nm) in a wavelength range of 42.5 nm (1532-1574.5 nm) are obtained. The frequency interval switchable multi-wavelength Brillouin random fiber laser is expected to greatly broaden the application and increase the flexibility of multi-wavelength laser in fields such as optical communication and sensing.