The invention discloses a mold for toothbrush manufacturing, and relates to the technical field of plastic molds. The mold for toothbrush manufacturing comprises a front mold body and a back mold bodymatched with the front mold body, a front mold core is arranged on the front mold body, and toothbrush-shape forming cavities are formed in the front mold core; a back mold core is arranged on the back mold body, toothbrush holder cavities are formed in the back mold core, modules are detachably arranged at the ends, located in the toothbrush holder cavities, on the back mold core, toothbrush head cavities for welding toothbrush bristles are formed in the modules, and a cavity capable of being matched with the forming cavities is formed by the toothbrush holder cavities and the toothbrush head cavities. According to the mold for toothbrush manufacturing, by arranging the detachably modules, multiple toothbrush bristles are welded in the toothbrush head cavities in the modules, then the modules are automatically assembled on the back mold body, the front mold body and the back mold body are assembled to carry out whole injection molding of toothbrush holders and toothbrush heads, the toothbrush bristles are directly connected on the toothbrush heads, and it is avoided that the toothbrush holders are manufactured, and then bristles are implanted; through whole injection molding, thetoothbrush bristles are more compactly connected with the toothbrush heads, the stability is better, the toothbrush bristles are not prone to falling off, the cleaning effect is better, and meanwhilethe product quality is improved.