Gas penetration depth at quenching pipe outlet and fluctuation characteristics of gas-liquid interface of scrubbing-cooling chamber were investigated by a differential pressure transducer and a high definition digital video(HDDV).The results showed that the penetration depth increased exponentially with increasing superficial gas velocity. On the basis of the experimental data，an empirical equation of main penetration depth and momentum flux of the quenching pipe outlet was proposed and the estimated maximum depth was 2.51 cm. Meanwhile，the VOF model and RNG κ –ε turbulence model were used and the simulated results were in good agreement with experimental data. Moreover，the circulating pulsation of the scrubbing-cooling chamber was significantly affected by liquid surface fluctuation of the quenching pipe outlet.