Claan egr system for diesel-gasoline mixed combustion engine, engine for complex combustion using diesel and gasoline and control method applying of the same

PURPOSE: An EGR system, diesel-gasoline mixed combustion engine applied with the same, and a control method thereof are provided to prevent particle matters from being stuck on the inner surface of the EGR system by utilizing clean exhaust gas as EGR gas and using a specific cylinder as a cylinder only for EGR gas. CONSTITUTION: An EGR system of a diesel-gasoline mixed combustion engine comprises a non-EGR cylinder(11a) and an EGR cylinder(11b). The non-EGR cylinder is connected to an exhaust manifold(25) which is directly connected to a post processing apparatus. In the non-EGR cylinder, an exhaust valve is connected to an EGR line, so that EGR gas supplied to the diesel-gasoline mixed combustion engine. The EGR line passes through a cooler(33) placed at the downstream of a compressor of a turbocharger.