Abstract: Disclosed are a catheter which can perform both multi diagnosis and treatment, and a catheter system comprising same. A multi diagnosis and treatment catheter comprises: a triple-clad fiber; and a lens connected to one end of the triple-clad fiber. The triple-clad fiber comprises: a core guiding a first diagnostic light; a first cladding surrounding the core and guiding a second diagnostic light; a second cladding surrounding the first cladding; a third cladding surrounding the second cladding and guiding a therapeutic light; and a coating layer surrounding the third cladding.