An oil filtering system for a storage unit configured to receive and hold oil from a fryer in a main storage space thereof includes a filtering unit and a conveying unit. The filtering unit is removably arranged on an inner bottom surface of the storage unit within the main storage space and configured to filter the oil in the storage unit via lower and upper filtering layers thereof. The conveying unit is removably connected to the filtering unit and has a portion extending upwardly from the filtering unit within the main storage space for conveying the filtered oil from the filtering unit.