an oil filter module may include a casing and a filter therein . the oil filter module may also include a cap coupled to the casing , and including a drain nipple protruding downward from a portion of the cap corresponding to a bottom support plate of the filter with a drain hole formed in the drain nipple . the oil filter module may further include a drain pin coupled to the drain nipple so as to be removable so that the drain hole is open or closed by the drain pin . a rotation groove having a rotating axis of the casing may be formed in a lower surface of the bottom support plate . the drain hole may be formed at a position corresponding to the rotation groove , and the drain pin may be seated at one end thereof onto a bottom of the rotation groove when the drain pin is coupled to the drain nipple .