The invention discloses a suction type two-stage shock wave focusing ignition engine combustion chamber and a working method thereof, and belongs to the technical field of detonation engines. The combustion chamber comprises a first cavity body, a first combustion chamber shell, a first shock wave focusing concave surface, two rotating valve flaps, a pre-cooling chamber concave surface, a second shock wave focusing concave surface, a divergent section, a second combustion chamber cavity body, a cold oil pipe, a first heat oil pipe, a second heat pipe and a rotary fuel atomization nozzle. By rotating the rotating valve flaps, intermittent jet flow of air is controlled, so that intermittent shock wave focusing ignition detonating mixed combustible gas in a shock wave focusing chamber is realized, and the reliability of detonation of the engine combustion chamber is further improved through the forward and reverse arranged two-stage shock wave focusing concave cavities. According to the combustion chamber and the working method, the combustion chamber can stably realize high-frequency shock-wave-focused ignition while axially air sucking like a traditional engine, the engine combustion chamber quality is effectively improved, the thrust performance of the engine is improved, and a new technical way is provided for developing a practical high-power detonation engine.