Based on the principle of stabilizing coke size,this paper studies the coking process and coke size of 7.63 m coke oven in Shougang Jingtang company,analyzes the factors affecting the coke grain size,such as coal blending quality,carbonization time,quenching process,coke transfer and coke screening.By optimizing coke transferring,the material level of coke bin is controlled at least 3 m;special attention is paid to the moisture stability in coal blending,within the range of ±0.3%,in particular to the effective management of screening process to improve the stability of coke grain size.