Abstract: In order to reduce the influence of deposition and coking of coal direct liquefaction equipment on production process,efficient methods on mitigating or eliminating the deposition and coking during coal direct liquefaction was proposed by analyzing the deposition and coking sites and the regularity of the device.The results show that proper increase the flow rate of the medium,eliminating the local dead zone,reducing the amount of material adhesion can significantly mitigate or eliminate deposition and coking.Additionally,measures,such as reducing local temperature and improving filtration accuracy,are used to slow down or eliminate deposition or coking.Meanwhile,the effect of modification and optimization of relevant measures on prevention of deposition and coking has been verified.The coking amount of the hot medium pressure separator is reduced from 1.86 t to 0.27 t through the implementation of the above measures.The pulverized coal deposition in the cold and high pressure separator is reduced from 0.56 t to 0.05 t,and the vacuum furnace feed continuous operation.The time is extended from the original less than 2 months to more than 6 months,and the reactor operating time is increased from 200 days to 420 days.Therefore,the problem of deposition and coking of coal direct liquefaction equipment are effectively mitigated or eliminated.