物理法主要通过物理机械的方法如：碾和磨等传统加工方法减小细度、增加比表面积，此外还有用超声波震荡，辐照预处理等方法达到改变纤维素结构，易被纤维素酶催化的目的。物理法一般不会单用，而是作为木质纤维素预处理的第一步，与其他预处理方法联用达到降低纤维素结晶度，提高纤维素酶解性能的目的。 Physical method mainly through physical methods such as grinding and a decrease in traditional processing methods, such as grinding fineness, increasing the specific surface area, in addition to use ultrasonic oscillations, irradiation pretreatment methods to achieve the changing structure of cellulose, vulnerable to the purpose of the cellulose enzyme catalysis. Don't usually use physical method, but as the first step in the pretreatment of lignocellulose combination with other pretreatment methods to reduce crystallinity of cellulose, enhance the performance of cellulose enzyme solution. 　　化学法预处理是采用各种化学试剂(包括水)对木质纤维素进行预处理以提高纤维素酶解效率的方法。目前，化学法仍然是纤维素预处理过程中的主要方法。根据采用的化学试剂不同，可以将化学法分为以下几种：液态热水法，酸法，碱法，亚硫酸盐法，氧化脱木素，纤维素溶剂法，有机溶剂法。 Chemical pretreatment is a method of pretreatment of lignocellulosic cellulose with various chemical reagents (including water) to improve the efficiency of cellulose enzyme. At present, the chemical method is still the main method in the preparation of cellulose. According to the use of chemical reagents, chemical method can be divided into the following kinds: method of liquid water, acid, alkaline sulfite method, oxidation of lignin, cellulose solvent method, organic solvent method. 　　其中，稀酸预处理是目前研究较为成熟的预处理方法，试剂价格低廉、可有效提高纤维素的水解特性和半纤维素的可发酵性，但是预处理后残余的酸需要进行中和处理，不仅需要消耗额外的试剂，提高成本，还会产生废物造成污染，如若进行脱毒处理，成本会更进一步加大；而液态热水法预处理具有无需中和处理、降低成本、环境污染小、并且不需对原料进行预处理、几乎不产生对发酵有抑制作用的副产物等优点，但是由于操作温度相对较高、对设备的要求比较高、熔解木素会重新沉积在纤维表面、半纤维素多以寡糖形式存在于液相中，需要后续酸水解获得可发酵糖等缺点。 Dilute acid pretreatment is the present study is relatively mature pretreatment method, the reagent price is low, can effectively improve the hydrolysis of cellulose and hemicellulose fermentability, but after the pretreatment of the residual acid neutralization treatment is required, not only need to consume additional reagent, raise cost, also can produce waste pollution, if detoxification treatment, the cost would be further increased; And liquid water has no neutralization processing method of pretreatment, cost reduction, environment pollution is small, and need not be on raw material pretreatment, almost do not produce has inhibitory effect on fermentation of by-products, etc, but due to the relatively high operating temperature, high compared to the requirement of equipment, melt lignin to deposit on the fiber surface, hemicellulose exists in the liquid phase in the form of oligosaccharides, require follow-up acid hydrolysis of fermentable sugars and other shortcomings.