The invention discloses a low-pressure cold-end exhaust gas recirculation (EGR) system of an engine. The low-pressure cold-end EGR system of the engine comprises an EGR cooler, an EGR valve, an EGR mixer and a controller, wherein the EGR cooler is internally provided with an exhaust gas channel and a coolant channel, and the gas inlet end of the exhaust gas channel is connected with an exhaust pipe of a diesel particulate matter filter, so that after exhaust gas is guided out from the exhaust pipe of the diesel particulate matter filter, the exhaust gas is cooled in a heat exchange mode; the gas inlet end of the EGR valve is connected with the gas outlet end of the exhaust gas channel of the EGR cooler; and an exhaust gas inlet of the EGR mixer is connected with the gas outlet end of the EGR valve, and an air inlet of the EGR mixer is connected with the upstream of a gas compressor of a supercharger. According to the low-pressure cold-end EGR system of the engine, the exhaust gas and fresh air are well mixed, due to the fact that the temperature of EGR exhaust gas is lower after being cooled by an intercooler and the DPF, the lower exhaust gas temperature is obtained, the cooler can be made smaller, performance of the supercharger is not reduced, and the potential of reducing fuel consumption is achieved.