TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The carbon is from petrifaction work-piece process of fluid catalytic cracking, and the thermal cracking to prepare ethylene and ethylene; the etherification comprising reacting isobutene in mixing gas with methanol under acid catalyst and obtaining methyl tertiary butyl ether (MTBE), and acid catalyst comprising strong acid macropore cationic resin catalyst; and aromatization comprising translating olefin into aromatic hydrocarbon compound under modified molecular sieve based catalyst, and modified molecular sieve based catalyst comprising modified ZSM-5 or beta -molecular sieve. The method comprises using fixed bed process for hydrotreating, filling reactor with hydrotreating catalysts comprising main hydrogenation catalyst and other one comprising auxiliary hydrogenation catalyst; the main hydrogenation catalyst added at upstream of auxiliary hydrogenation catalyst, and two hydrogenation catalysts separated via inert carrier; the main hydrogenation catalyst preparing carrier with gamma -aluminum oxide, carrier assistant comprising copper (Cu), zinc (Zn), zirconium (Zr), potassium (K), fluoride (F), phosphorus (P) and boron (B), and active metal comprising platinum (Pt), palladium (Pd), molybdenum (Mo), cobalt (Co) and/or nickel (Ni) element, with specific surface area of catalyst of 220-280 m2/g, pore volume of 0.25-0.35 mL/g, mean pore size distribution of 20-40 nm, resistance to crushing strength of 180-350 N/cm2, and catalyst occupying 75-90% of the total amount of the filled catalyst; and auxiliary hydrogenation catalyst comprising anatase titanium dioxide (TiO2) as carrier, carrier assistant comprising Zr, P, K, lanthanide (La), cerium (Ce), Pd, silver (Ag), golde (Au) and manganese (Mn), active metal comprising Pt, Pd, Mo and/or Co, specific surface area of catalyst of 150-250 m2/g, pore volume of 0.3-0.45 mL/g, mean pore size distribution of 15-35 nm, resistance to crushing strength of 140-250 N/cm2, and catalyst occupying 10-25% of total amount of the filled catalyst. The index range of operation process of hydrogenation comprises gaseous hourly space velocity of 2-8 v/v, at 180-360 degrees C, hydrogen oil ratio of 100-600/hour, utilizing cold and high separation technological process and recycling hydrogen; and the total olefin mass content in the product after hydrogenation process is not greater than 0.5%, the total sulfur content in product is not greater than 10 mu g/g, and obtaining hydrogenation product-containing different olefin and total sulfur content via adjusting hydrogenation depth. The effluence from bottom of the hydrogenation reaction tower enters fractionating column after processes via high and low pressure separator, the effluence from top of fractionating column is dimethylmethane, and the effluence from the bottom is isobutane and n-butane; effluence from bottom enters rectifying column, rectifying column is common float valve plate tower, separates isobutane and n-butane, effluence from top of tower is isobutene, effluence from the bottom is n-butane, and mass content of the isobutane is not less than 99%, mass content of the olefin is not greater than 0.5% and mass content of the n-butane is not less than 98% and the mass content of the olefin is not greater than 0.3%.