The invention belongs to the technical field of textile assistants and particularly relates to a neutral leveling agent for acid dyes. The neutral leveling agent for acid dyes has good fiber fabric dyeing effect, dyeing uniformity, high retarding performance and high color fastness, and dyed fiber fabric has no spot defects such as color stripes, color spots and the like; components are simple, reasonable and scientific, the raw material cost is low, the neutral leveling agent is environment-friendly, natural, pollution-free and non-toxic to the human body, chitosan is applied to the wool dyeing process with the acid dyes and has excellent leveling effect, meanwhile, the fabric is endowed with good antibacterial performance, a tea extraction solution and a wormwood extraction solution are added to the components, and the antibacterial and insect-proof performance of the dyed fabric is further improved; the neutral leveling agent can effectively reduce damage to wool fibrin and improve the quality of the wool fabric.