Abstract: In order to improve concentration of CWS for gasification,the relations of CWS concentration to dosage of new additive HD-8A or pH value of coal slurry was studied in the laboratory about production process of CWS in Shangwan of Shenhua. In addition,industrial test were carried out on the basis of adjusting process parameters of the equipment for CWS preparation. The industrial test result shows that:concentration of CWS is increased 1. 62% in conditions of 3‰ dosage of new additive HD-8A and 8. 35 pH value of coal slurry; when concentration of CWS is increased 1%,proportion of effective gas（CO + H₂） is increased 1. 1%,coal consumption is reduced 10. 08 kg producing 1 KNm³ coal gas,oxygen consumption per unite gas production is also decreased 12. 68 Nm³ at the same time the methanol production is increased.