The invention relates to a method and device for concentrating biogas slurry and recycling product water, relates to a method and device for concentrating biogas slurry and recycling product water, and is mainly used for solving the problem that the existing hyperfiltration membrane treatment process is high in cost and severe in pollution and the cleaning waste liquid is incompletely used. The method comprises a biogas slurry pretreatment process, a biogas slurry hyperfiltration membrane treatment process and a membrane cleaning process. By adopting the method and device, the obtained biogas residue, concentrated liquid and product water are sufficiently used, particularly by recycling the product water, the resource treatment of the biogas slurry is realized, the biogas slurry treatment cost is decreased, and the environmental pollution is reduced. The method and device are applied to the biogas slurry treatment field.