Abstract: Changxing formation of Yuanba gas field is a high sulfur gas reservoir with high single well production,but the traditional capacity evaluation method needs enough gas discharging testing time,which is bad for environmental protection,therefore,on the basis of the binomial productivity equation,through statistical analysis of 9 wells testing data in Changxing formation,the experience formula has been summarized,namely apoint capacity fast evaluation formula.The formula can be used for rapid evaluation of gas reservoir production capacity of Changxing formation in Yuanba gas field.It can improve the evaluation efficiency and reduce the environmental pressure.