Abstract: Analyzed here in the essay are the issues concerning the appearance quality control of the tubing and casing during the entire flow process of quenching and tempering,focusing on discussion on the formation mechanism of such typical defects as oxide scale,dent and rolling mark,etc.,and relevant control methods. The studies reveal that the growth of the oxide scale on the surface of the steel tube is affected jointly by the temperature and the time during the heating period;the mechanical dent is easily caused by the uneven cooling stress during the quenching-cooling process;and the incorrect hot-straightening process parameters may lead to producing the straightening mark. Accordingly the technique used for removing the oxide scale during the heating process is researched and developed, and the quenching-cooling medium flow velocity and the temperature distribution are optimized to reduce the incidence rate of the dent,and moreover setting of the parameters of the roll type straightening process is improved. The actual engineering application demonstrates that the above mentioned serial technical measurements have significantly improved the surface quality of the tubing and the casing,and enhanced their market competitiveness.