NOVELTY - Bio-gasification of coal tar involves pre-processing: adding 0.05-1% pre-treated solution to raw material coal tar, uniformly mixing and standing for 1-7 days, obtaining preprocessed coal tar; taking pre-processed coal tar into bioreactor, keeping the bioreactor anoxic or anaerobic environment, then adding 0.1-5% inoculating liquid to the bioreactor, stirring them uniformly, obtaining biological raw material liquid, adjusting pH value of the raw material liquid to 4-10, controlling the reactor temperature to 25-65 degrees C for 1-30 days to obtain gasification gas.    USE - For bio-gasification of coal tar (claimed); for conversion of coal tar to methane.    ADVANTAGE - The biological method for coal tar gasification provides low energy consumption, which meets the national policy of energy saving and environmental protection; the marsh gas liquid pool, anaerobic sewage treatment plant sludge or trash percolate in a landfill site leachate is rich in methane production bacteria of waste liquid, the waste liquid can be recycled, reduces environment pollution, and the process is simple, the condition is easy to control, provides low production cost and easy to popularize, and can be widely applied to coal tar biomass gasification field.    DETAILED DESCRIPTION - Bio-gasification of coal tar involves pre-processing: adding 0.05-1% pre-treated solution to raw material coal tar, uniformly mixing and standing for 1-7 days, obtaining preprocessed coal tar; taking pre-processed coal tar into bioreactor, keeping the bioreactor anoxic or anaerobic environment, then adding 0.1-5% inoculating liquid to the bioreactor, stirring them uniformly, obtaining biological raw material liquid, adjusting pH value of the raw material liquid to 4-10, controlling the reactor temperature to 25-65 degrees C for 1-30 days to obtain gasification gas. The raw material coal tar is low temperature coal tar, middle temperature coal tar, high temperature coal tar, coal tar distillate oil or coal tar asphalt. The inoculating liquid is marsh gas liquid pool, anaerobic sewage treatment plant sludge or trash percolate in a landfill site leachate. The pre-processing solution comprises composite microbial inoculum, weak acid and/or weak base solution.