A coating device includes a body and a thermoelectric cooling plate. The body defines a receiving space and a storage groove and includes a contact plane and a feeding pipe. The contact plane includes a cooling region and a heating region which are cooled and heated by the thermoelectric plate, respectively. The storage groove is provided for storing a coating material. The storage groove communicates with outside of the body through the feeding pipe. When the body is moved from a first position to a second position of the target object, the coating material is heated by the heating region, cooled by the cooling region, and coated on the surface of target object.