Abstract: In this paper, coke dry gas hydrogen unit operating conditions are analyzed, the amount of hydrogen unit expansion is studied from the aspects of material balance, reaction kinetics and heat balance. The operation data showed that the conversion rate of hydrocarbon steam reforming reaction is 86%, higher than the design value of 78%. VBA programming iterative method is used to calculate the conversion data of steam reforming reaction of methane at different temperatures. The approximate calculation method is used for the material and heat accounting of hydrogen unit reform and reasonable proposals are obtained.