The present invention relates to an attachment cap unit for shower. In particular, in order to achieve the objective of the invention, the attachment cap unit for shower according to the present invention comprises : a head fix unit surrounding the outside of a shower head which sprays water through a plurality of injection holes formed on one side of the shower head a scalp contact unit which is made from an elastic soft material at the lower end of the head fix unit and which is formed to be in close contact with the scalp such that the end edge portion thereof extends downwardly below one side of the shower head on which the injection holes are formed a drainpipe provided in the head fix unit a hose which is connected to the drainpipe for guiding water sprayed from the injection holes of the shower head to the outside and an elastic protrusion attached onto one side of the shower head on which the injection holes are formed. The attachment cap unit for shower can remove foreign materials from hair or the scalp and also has an effect of acupressure or massage for hair or the scalp.