In optimization control of various factors by Danish Topp rope low pressure synthesis methyl alcohol installment synthesis of methyl alcohol is playing the very major role for enhancing the thick mellow output, improving the thick mellow quality, saving the investment cost in the methyl alcohol selective evaporation,and increasing the promotion enterprise benefit. Many Influence factors methyl alcohol sysnthesis reaction were discussed, like temperature, pressure, airspeed, ratio of carbon and hydrogen, inert gas content, alcohol content at the towerentrance methyl and so on.The production results indicated when the synthesis reaction temperature is about 230 ℃, the ratio of carbon and hydrogen is about 2.05, strictly controlling the feed gas quality, carries on adjusting the air release in valve opening the indifferent gas system dump along with the indifferent gas content,the side reaction can be effectively controlled, the catalyst service life can be lengthened,the synthesis.installment can be kept stable and long period operation.