Biogas digester for combined fermentation treatment of garbage and sewage

The invention relates to the technical field of biogas digesters, in particular to a garbage and sewage combined fermentation treatment biogas digester which comprises a digester body, and a liquid inlet pipe is fixedly connected to the position, close to the left side, of the outer surface of the upper end of the digester body in an embedded mode and extends into the digester body. An air outlet pipe is fixedly connected to the position, close to the top end, of the outer surface of the left side of the pool body in an embedded mode, and a pressure relief mechanism is arranged at the position, close to the center, of the upper end face of the pool body. According to the biogas digester, waste of biogas is reduced, meanwhile, potential safety hazards of biogas leakage caused by too high air pressure are avoided, biogas slurry in the biogas digester can be automatically taken, a user can conveniently measure the PH value of the biogas slurry, the user can conveniently adjust the PH value of the biogas slurry i