Cyclodextrin played an important role in environmental protection in recent years.Application of cyclodextrins in enviroment science upon aspects;enrichment and removal of organic pollutants and heavy metals from soil,water,and atmosphere. β-cyclodextrin (β-CD) can be linked when it was sulfonation-modified.A convenient method of photocatalytic degradation of pesticide in lab by self-designed photocatalytic equipment was proposed based on analysis and comparison of different methods used to determine pesticide. The effects of illumination,reaction time,and pesticide concentration were analyzed. The results showed that the photodegradation of monocrotophes increased 2.08-2.86 times in the presence of 20g/L and 40g/L sulfonated β-cyclodextrin.In addition,the photodegradation of omethoate increased 1.8-2.2 times in the presence of 40g/L sulfonated β-cyclodextrin. The light activation were caused by the formaton of inclusion complexes of monocrotophes with sulfonated β-cyclodextrin. It was found that the method was simple and paid lower costs; and it could be used in lab for the photo-catalytic degradation of pesticide.