NOVELTY - Automotive fuel is manufactured from biogas by passing biogas produced by anaerobic digestor through pipeline on bottom of buffer tank, changing heat of biogas and water to cool gas, passing biogas through de-sulfurizing device equipped with iron oxide, and ensuring not greater than 5 mg/Nm3 content of hydrogen sulfide (H2S); conveying biogas after first stage clean to gas holder with 10 kg pressure for storing, and providing working gas source to compressor; pressurizing pressure of purified biogas to 25 MPa, and storing into high pressure gas storing system; and controlling gas seller.    USE - Method for manufacturing automotive fuel by biogas (claimed).    ADVANTAGE - The method reduces energy crisis and environment condition, reduces production cost, and has low environmental cost and high return rate.    DETAILED DESCRIPTION - Manufacture of automotive fuel by biogas comprises:    (A) passing biogas produced by anaerobic digestor through pipeline on bottom of buffer tank, removing clean water on lower part, and changing heat of biogas and water to cool gas, with effective volume of buffer tank for supplying gas from vacuum pump to gas holder;    (B) removing water of cooled biogas in whirlwind dehydration device, passing biogas through de-sulfurizing device equipped with iron oxide, and ensuring not greater than 5 mg/Nm3 content of hydrogen sulfide (H2S);    (C) conveying biogas after first stage clean to gas holder with 10 kg pressure for storing, and providing working gas source to compressor;    (D) filling biogas after first stage clean into adsorption tower, with 4A type molecular sieve adsorbs water in biogas, adsorbing carbon dioxide (CO2) by converting pressure, and maintaining temperature of dehydrate biogas at not greater than - 54 degrees C under normal pressure, and 3% CO2 content, and low heat value of purified gas of 33.4 MJ/Nm3;    (E) pressurizing pressure of purified biogas to 25 MPa, and storing into high pressure gas storing system;and    (F) controlling gas seller to add high pressure biogas to compressed biogas gas entrained vehicle.