Sewage pretreatment method and equipment with biological clarification tank function

The invention discloses a sewage pretreatment method and equipment with a biological clarification tank function. The equipment comprises a top plate, a bottom plate, a manhole, an inner cylinder wall, a middle cylinder wall, an outer cylinder wall, a water outlet hole, a circulating reflux pump, a water passing hole, a guide plate and an inner partition plate, the inner cylinder wall, the middle cylinder wall and the outer cylinder wall are sequentially sleeved from inside to outside, a top plate is arranged above the outer cylinder wall, and a manhole is formed in the top plate; an inner partition plate is transversely arranged on the inner cylinder wall, divides the volume of the inner cylinder wall into a second reaction area and a first reaction area which are distributed up and down, and is provided with a circulating reflux pump and a circulating reflux pump base; a first overflow area B is arranged between the inner cylinder wall and the middle cylinder wall, and a first baffling area A is arranged be