The invention relates to a cleaning process for extracting high quality 
fiber with high efficiency, high yield and low 
energy consumption from 
plant raw materials by a 
combination method of 
chemistry and machinery in a sectional type. The process comprises the following steps: a 
raw material is fully immersed in a NaOH solution or a KOH solution or 
limewater with low concentration (
black liquor is used for supplementing into the corresponding alkaline for repeated and circular use) under the normal temperature or certain temperature, wherein the concrete immersion temperature and immersion time can be determined according to the types and the 
water content of the raw materials so that the alkaline liquor is fully, uniformly and properly absorbed and diffused into plants; 
steaming under normal pressure or 
steaming with pressure or no liquid 
steaming with pressure is used; the steamed material can be selected according to the 
paper quality requirement by using a blowout slurrying mode or a mode of pulp refining after blowing to form 
slurry or by using thread rolling and pulp refining to relief material once or multitime to prepare 
slurry. The novel process combines the advantages of 
chemical treatment and mechanical pulping, so that the uniform 
mass transfer and uniform 
heat transfer can be ensured and the damage to 
cellulose and 
hemicellulose by excessive alkali can be reduced, the yield of 
fiber is raised to about 75% from about 45% of the prior art, so that the novel pulping process is capable of avoiding the usage of auxiliary agents like sulfured and 
anthraquinone, conveniently extracting and using the 
cellulose and 
lignin in 
black liquor, and overcoming the influence on environment during the process of pulping and post-treating 
lignin.