The invention relates to a communicated gas channel system integrated on a gas inlet manifold branch. The gas inlet manifold branch comprises a communicated gas cover plate, a communicated gas inlet, a lower shell and an upper shell, wherein the lower shell is connected with the communicated gas cover plate; the communicated gas inlet is formed in the communicated gas cover plate; the lower shell is connected with an air cylinder cover of an engine by a cold insert; the communicated gas channel system comprises a sealed space formed by the lower shell and the communicated gas cover plate; two baffles, four communicated gas inlets and four communicated gas outlets are formed in the sealed space; one end of each baffle is fixed on the lower shell; the two baffles are arranged by taking the communicated gas inlets as symmetrical axes; a lower shell flange is arranged in the lower shell; the four communicated gas inlets and the four communicated gas outlets are formed in the lower shell flange; the four communicated gas inlets and the four communicated gas outlets are correspondingly connected by communicated gas channels respectively. Compared with the prior art, the communicated gas channel system has the advantages of good balance, strong water storage capability, no fears of freezing and the like.