Method for obtaining biogas through garbage treatment

The invention discloses a method for obtaining biogas through garbage treatment, which comprises the following steps: S1, garbage classification treatment: collecting fermentable garbage, and carrying out gas explosion crushing to obtain garbage powder slag; s2, garbage powder is obtained through treatment of a backflow control system; s3, introducing the garbage powder into a pre-sedimentation tank, washing with clear water, transferring into a fermentation tank, adding an activating agent, inoculating methane bacteria, and carrying out initial sealed fermentation; s4, collecting an initial fermentation product, circulating for multiple times to obtain a multiple fermentation product, preparing a biological fertilizer, and then preparing biological natural gas; the device has the beneficial effects that the fermentable garbage is subjected to rolling crushing, high-pressure gas crushing and a backflow control system to obtain garbage powder, then the garbage powder is mixed with clear water by utilizing the