With the rapid development of economy and a large number of energy consumption, the countries all over the world are faced with the depletion of fossil energy resources. Meanwhile, a large number of fossil energy extraction cause geological disasters frequently and the greenhouse effect, which lead to global warming, acid rain and other serious environmental problems. As a representative of the biomass energy, crop straws have advantages of wide distribution, large amount, low price and cleaning, which will be an ideal choice in the future. But it is hard to be efficiently used because of the special structure of crop straws. Through fermentation engineering and gene engineering, people can greatly improve the efficiency of utilization of crop straws, which offers a very promising way to make a breakthrough for energy consumption.