A joining surface treatment device and a joining surface treatment method for treating a joining surface of a component which joining surface is used for joining two components, the joining surface treatment device comprising at least one heat source for heating a portion of a surface of a first component at which portion the first component shall be joined with a second component; and a primer application device for applying a primer to a portion of the surface of the first component which portion is heatable by the at least one heat source, wherein the at least one heat source is arranged so that it can heat the first component before and/or after applying the primer.