The invention provides an exhaust gas recirculation system. The exhaust gas recirculation system comprises an engine cylinder, an exhaust manifold, a catalyst, a cooler, a supercharger, an air channeland an intake manifold, the supercharger comprises a turbine and a turbine press, the catalyst comprises a first-stage carrier and a second-stage carrier which are separated from each other, the intake end of the catalyst is connected to the turbine, a part, located between the first-stage carrier and the second-stage carrier, of the catalyst is connected to the intake end of the cooler, the airoutlet end of the cooler and the air channel are connected to the intake end of the turbine press, and the air outlet end of the turbine press is connected to the intake manifold through an intake pipeline. Due to the fact that the catalyst comprises the first-stage carrier and the second-stage carrier which are separated from each other, the middle of the first-stage carrier and the middle of thesecond-stage carrier are connected to the intake end of the cooler, an exhaust gas lead-in point of the cooler is located between the first-stage carrier and the second-stage carrier, the exhaust gaspressure at the position is large, and therefore the pressure difference between the lead-in point and the lead-out point of the cooler can be improved, and the exhaust gas recirculation rate is further improved.