An optical information reproducing apparatus and an optical information reproducing method using the same are provided. The optical information reproducing apparatus includes: a light source; a beam splitter which splits a beam emitted from the light source into a reference beam and a temporary beam; a temporary beam splitter which splits the temporary beam into a pair of assistant beams; an incident optical system which inputs the reference beam and the assistant beams to a recording medium in which optical information is recorded; a reproduction beam detector which detects reproduction beams reproduced in response to the reference beam, sets the position of the reproduction beam having the largest light intensity as a reference position, and sets a signal region on the basis of the reference beam; and an assistant beam detector which compares the light intensity of the assistant beams incident on the signal region with each other and sets an incident angle of the reference beam. Accordingly, it is possible to detect a tilt error and to correct the tilt error at the time of reproducing data from the recording medium.