Abstract: Biomass are known for its disadvantages，including high water content，low energy density，difficulty in comminuting into small particles and expensive transportation. However，pretreatment is one of the most effective ways to improve the quality of biomass pyrolysis products. The purpose of biomass pretreatment is to optimize certain features of biomass，such as hardness，particle size，density，composition，and chemical properties，to obtain more and higher quality of bio-oil in its pyrolysis liquefaction process. To improve the pretreatment technology with higher economic efficiency，the study onbiomass pretreatment technologies are reviewed in this paper. Many methods for high quality bio-oil have been discussed. In this review，the pretreatment technology，such as drying methods，acid hydrolysis，torrefaction，hydrothermal and biological methods，are analyzed in focus. Among them，drying methods and torrefaction have the potential in comparison. But the current study are still insufficient，we need to seek new pretreatment technology with lower cost，higher yield and less pollution. Suggestions on the development of pretreatment technology are also included. At present，the single biomass pretreatment methods have their defects，the combination of different pretreatment methods is the important direction in future research，in which the structural characteristics and composition of raw material properties are properly combined.

Key words: biomass, pretreatment, pyrolysis, bio-oil

摘要： 生物质水分含量高、能量密度低、储存运输成本高等缺点制约着其转化利用。预处理技术是提高生物质热解产物品质的有效方法之一。为了研究高效经济的预处理技术，本文总结了国内外生物质预处理技术的研究，对干燥法、稀酸法、水热法、烘焙法和生物法等预处理技术进行了重点分析，发现干燥法和烘焙法等技术极具潜力，但是目前的研究仍存在不足，今后还需研究成本低、产率高、污染小的预处理技术，并对预处理技术的发展提出了建议。

关键词: 生物质, 预处理, 热解, 生物油