NOVELTY - A sludge drying method comprises using a precoated vacuum-type drum filter, where the precoating agent is a commercial precoating agent or mixture of commercial precoating agent and recovered sludge particles; filtering sewage generated by a biochemical treatment using the precoated filter under the condition of not adding flocculating agent to obtain filter sludge and filtrate fitting the effluent standard; burning the filter sludge to generate solid slag and tail gas; and discharging the tail gas after dedusting treatment; and screening the solid slag.    USE - A method of sludge drying useful for solid-liquid separation of domestic sewage processed by biochemical treatment.    ADVANTAGE - The method economically and high-efficiently separates the solid contaminant in sewage processed by the biochemical treatment to obtain filter sewage which can be directly discharged and filter sewage with moisture content less than 50%. The solid slag obtained by burning the sewage can be used as a precoating agent to recycle.    DETAILED DESCRIPTION - A sludge drying method comprises:    (A) using a precoated vacuum-type drum filter, where the precoating agent is a commercial precoating agent or mixture of commercial precoating agent and recovered sludge particles;    (B) filtering daily or industrial sewage generated by a biochemical treatment using the precoated filter under the condition of not adding flocculating agent to obtain filter sludge and filtrate fitting the effluent standard, where the filtrate is directly discharged;    (C) burning the filter sludge to generate solid slag and tail gas; and discharging the tail gas after dedusting treatment;    (D) screening the solid slag, where part of screened solid slag is the recovered sludge particles in the step (A) and the remaining solid slag is discharged as waste residue.    DESCRIPTION OF DRAWING(S) - The drawing is a flow diagram illustrating the sludge drying method (Drawing includes non-English language text).