The invention discloses a wind power blade manufacturing method, and relates to the technical fields of large wind power blade design and manufacture. The wind power blade manufacturing method comprises the steps that all shell laying materials except skin are prefabricated in a regional mode, then outer skin is laid on a shell main mold, a shell prefabricated member is arranged, inner skin is laid, a flow guiding auxiliary material and a vacuum bag film are laid to build a vacuum system, overall pouring is conducted, and then the shell technology defects are greatly reduced. The wind power blade manufacturing method has the beneficial effects that the shell laying quality is improved, the shell pouring difficulty is reduced, the technology defects such as laying wrinkles and bad pouring of a shell structure are reduced, the probability that shell half piece scrap is caused by the local defects of blades is decreased, and the mold occupation time of local blade maintenance is shortened.