The invention discloses a method for preparing rice hull ash active carbon from solid-state co-fermentation rice hull. The method comprises the steps of: firstly, incubating white-rot fungi in a rice hull fermentation culture medium, incubating trichoderma viride, or aspergillus niger or trichoderma reesei or trichoderma koningii or blue mould, and carrying out dry distillation to prepare the rice hull ash active carbon after solid-state co-fermentation. The method is simple in preparation process, and easy to operate; and the prepared rice hull ash active carbon has a good surface micro-pore structure and strong adsorptive property.