Abstract: To resolve the problems in direct coal liquefaction,provide coal and oil co-processing technologies,meanwhile,analyse the advantages.Based on the analysis of coal and oil co-processing technologies at home and abroad,divide these technologies into four types according to the combination mode of coal and oil,function of oil during conversion.Investigate the principle,goal,strongpoint and limitation of each technology.Discuss the application effects of these technologies by typical examples.At last,present suggestions on the existing technical issues.