A three-component mixing apparatus and a three-component mixing adhesive kit, which allow anyone to easily and uniformly mix three kinds of drugs in mixing a three-component adhesive used in, e.g., surgical procedure (or treatment) or dental procedure (or treatment), includes a syringe filled with a first drug a plunger and an infusion-needle connector having a connecting part for a second drug container and a connecting part for a third drug container and a confluent path formed on a base end part. The first drug, the second drug and the third drug are mixed in the syringe by removably attaching the infusion-needle connector to a discharge opening of the syringe, the second drug container to its connecting part and the third drug container to its connecting part and then pulling the plunger inserted into the syringe to introduce the second drug and the third drug into the syringe.
