The invention provides an exhaust gas recirculation system for a rotary engine. The system comprises the rotary engine, a catalytic conversion system and an electronic control unit (ECU); an exhaust pipe and an intake pipe are arranged on a casing of the rotary engine and are connected with each other through a branch pipe; an exhaust gas recirculation control valve and an intercooler are sequentially arranged on the branch pipe according to the distance away from the intake pipe; the catalytic conversion system is mounted at the tail end of the exhaust pipe; a NOx concentration sensor is arranged at the tail end of the exhaust pipe and is located at the output end of the catalytic conversion system; a rotating speed sensor is mounted on a rotating shaft of the rotary engine and is used for measuring the rotating speed of the rotary engine; and the ECU is connected with the catalytic conversion system, the exhaust gas recirculation control valve, the NOx concentration sensor and the rotating speed sensor. With the system, the exhaust gas recirculation technology can be combined with the rotary engine, so that partial exhaust gas participates in working circulation again.