The hydrogen recovered from tail gas of a clean fuel production system based on indirect coal liquefaction technology could be used as a source gas of hydrogenation. It is beneficial to environment protection and waste gas utilization. The advantages of pressure swing adsorption(PSA) include high efficiency, automatical operation, low capital investment and operating cost. In order to simulate the multicomponent separation process in a clean fuel production system, an implicit backward finite difference method was used to solve the equations of PSA. After about 10 cycles, the steadystate was achieved. After analysis of simulated data, the factors influcing on product concentration were summerized.