The disclosed device for detecting the position and dose distribution of a therapeutic proton beam emitted in a pencil beam scanning mode comprises: a proton beam progressing position detection unit comprising a plurality of first optical fibers arranged along the first direction and a plurality of second optical fibers arranged along the second direction which is different from the first direction; and a proton beam dose distribution detection unit comprising a plurality of optical wavelength converter, each of which comprises an optical wavelength conversion disk and an optical wavelength-converting optical fibers arranged along the outer circumference of the optical wavelength conversion disk. The proton beam progressing position detection unit detects a proton beam progressing position through the arrangement of the first and second optical fibers, and the proton beam dose distribution detection unit detects a dose distribution of the proton beam progressing direction through a plurality of optical wavelength conversion disks.