Low-temperature scouring and bleaching agent and preprocessing technique for cotton or cotton blended fabric used therefor

The present invention realtes to a low temperature scouring and bleaching agent belonging to the pretreatment process technology field of the textile printing and dyeing industry, a manufacturing method thereof and a pretreatment process. Said low temperature scouring and bleaching agent consists of promoter QR2010 consisting of carbon tetrachloride, acetic acid esters, alkyl benzenes, emulsifying agents and scouring agents; promoter QR2011 consisting of potassium hydroxide, carbonates and penetrating agents; and promoter QR2020 consisting of acyls and nitriles activating agents and builders. Said three promoters are prepared using routine methods and are deposited solely. When used, the three promoters, together with hydrogen peroxide, are mixed according to different proportions to prepare solutions. Said low temperature scouring and bleaching agent is capable of annealing, boiling and bleaching a variety of cotton as well as cotton blending textiles at any temperature ranging from 40 DEG C to 80 DEG C, and