Energy shortage has caused widespread concern in all countries. The scientists turn to biofuels. However, due to large-scale use of corn, soybeans and other agricultural products for production of biofuels such as ethanol, and the situation that biofuels compete food with human and compete earth with crops is serious. This paper reviewed the advantages and disadvantages of methods for screening, purification, large-scale cultivation and harvesting. Biofuel extraction art as well as the industrial development trend were analyzed.