The invention discloses an air
source system multifunctional integrated prefilter and a filtering method thereof. The prefilter comprises a filter cylinder 1, a filter cylinder 2, an upper connection board and a lower connection board; an air inlet and an air outlet are respectively arranged at two sides of the upper connection board, airways are arranged in the upper connection board, the air inlet and the air outlet are communicated to the filter cylinder 1 and the filter cylinder 2 through the airways, so that after
compressed air is introduced from the air inlet, the
compressed air successively passes through the filter cylinder 1 and the filter cylinder 2, and then is discharged from the air outlet; storage chambers are arranged at bottom of an inner chamber of the filter cylinder 1 and the bottom of the inner chamber of the filter cylinder 2, a heating rod apparatus is arranged in the lower connection board, a draining valve apparatus and an electromagnetic control apparatus are arranged on the lower connection board, a drain is arranged in the lower connection board, the storage chambers are communicated to the draining valve through the drain, so that when the electromagnetic control apparatus controls the draining valve apparatus to an opening state,
liquid water and liquid oil in the storage chambers successively pass through the drain and the draining valve apparatus in order, and then can be discharged.