Septic tank and sewage treatment method using pretreatment and biological contact

The invention discloses a septic tank and sewage treatment method using pretreatment and biological contact in the technical field of treatment of domestic sewage. The septic tank which adopts pretreatment and biological contact includes a pretreatment aeration pool, a pretreatment sedimentation pool, an anaerobic fermentation pool, a biological contact oxidation pool, a secondary sedimentation pool and a blower, wherein a water inlet pipe is arranged on the pretreatment aeration pool, a first overflow plate is arranged between the pretreatment sedimentation pool and the pretreatment aerationpool, and the anaerobic fermentation pool is a sealed cavity. Sewage is pretreated under the condition of aeration firstly, organic matter and suspended matter in the sewage are adsorbed by sludge, and therefore the obtained sewage has a low carbon-nitrogen ratio; sedimentation of the sludge is performed in the pretreatment sedimentation pool, only the liquid is discharged, and solid matter whichcarries parasite eggs is l