Optoelectronic oscillator (OEO), a microwave signal source, is a popular research topic in microwave photonics. A quintuple OEO with tunable frequency and phase is proposed and theoretically analyzed, which is based on the stimulated Brillouin scattering (SBS) effect and carrier phase-shifted single-sideband modulation. In this structure, a cascade modulator structure is used to generate five lights with the same power and frequency interval as the pump lights, and then the quintuple OEO is obtained by the Brillouin gain-loss compensation principle. The frequency-tunable microwave signal is obtained by using the Brillouin wavelength-dependent property, and phase-tunable output microwave signal is obtained by adjusting the dual-parallel Mach-Zehnder modulator. The designed OEO can output high-frequency microwave signals with a frequency tuning range of 44.00-47.25 GHz, and on this basis, it can achieve a tunable phase range of 0°-360°.