▎ 摘　　要

NOVELTY - A microbial fuel cell-microbial electrolysis cell coupling device comprises microbial fuel cell units and microbial electrolysis cell units connected with resistance wire, and provided with multiple spaced iron units and graphene units. USE - Microbial fuel cell-microbial electrolysis cell coupling device used for recycling residual sludge. ADVANTAGE - The method has large residual sludge degradation factor, small floor area and high methane yield and purity, and generates water resource. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for recycling residual sludge comprising processing residual sludge in microbial fuel cell-microbial electrolysis cell coupling device, collecting supernatant and biogas, and filtering supernatant by membrane filter unit.