The utility model discloses a buried mixing structure-type SBR sewage treatment system. A buried device is formed by a plurality of pools with brick-concrete structures, and comprises a first oil separator, a second oil separator, a regulating reservoir and an SBR aeration tank, wherein the wastewater orderly passes through the first oil separator, the second oil separator, the regulating reservoir and the SBR aeration tank; the first oil separator, the second oil separator and the regulating reservoir are constructed by adopting a connected pool; the first oil separator and the second oil separator are communicated through a siphon at the upper part of a partition wall A shared by the first oil separator and the second oil separator; the second oil separator and the regulating reservoir share a partition plate B; the second oil separator is communicated with the regulating reservoir through a water hole at the bottom of a wall shared by the second oil separator and the regulating reservoir; the wastewater in the regulating reservoir is communicated with the upper part of the SBR aeration tank through a lift pump and a pipeline thereof; the SBR aeration tank adopts an independent foundation; an aeration water pump, an aerator, a drainage pump and a mud discharge pump are arranged inside the SBR aeration tank; the aerator is connected with the aeration water pump and arranged in the middle of the SBR tank; the drainage pump is arranged in the middle of the SBR aeration tank; the mud discharge pump is arranged at the lower part of the SBR aeration tank. The structure of the buried mixing structure-type SBR sewage treatment system adopts an impervious structure, and all equipment can be dismantled to move, and are convenient to repair.