Abstract: Objective To observe the clinical efficacy and safety of temozolomide combined with radiotherapy in patients with high-risk low-grade glioma after surgery. Methods The clinical data of 62 patients with high-risk grade Ⅱ glioma treated in our hospital from January 2015 to January 2018 were collected. All patients were treated with postoperative intensity-modulated radiotherapy. The observation group(32 patients) received concurrent chemotherapy during radiotherapy, and received temozolomide 75 mg/m² oral chemotherapy from the first day of radiotherapy, and then received oral temozolomide 150-200 mg/m² chemotherapy every four weeks after radiotherapy, 5 days a week for 6 consecutive cycles, meanwhile the control group(30 patients) only received postoperative radiotherapy. Adverse reactions, changes of cognitive function before and after treatment, 1, 2-year progression free survival rate and overall survival rate were observed and compared between the two groups. Results The main adverse reactions during the treatment were myelosuppression, gastrointestinal reaction and headache. There was no significant difference between the two groups(all P>0.05). There was no significant difference in cognitive function between the two groups before treatment(P>0.05). There was no significant change in cognitive function in the observation group after treatment(P>0.05), in the control group, there were some patients with cognitive decline, and the difference was statistically significant(P<0.05). The 1-year and 2-year progression free survival rates of the observation group were 93.8% and 81.2% respectively, and the 1-year and 2-year progression free survival rates of the control group were 66.7% and 53.3%, respectively, and the difference between the two groups was statistically significant(all P<0.05). The 1-year and 2-year overall survival rates of the observation group were 93.8% and 84.4% respectively, and the 1-year and 2-year overall survival rates of the control group were 70.0% and 60.0%, respectively, and the difference was statistically significant(all P<0.05). Conclusion The adverse reactions of temozolomide combined with postoperative precise intensity-modulated radiotherapy in the treatment of high-risk low-grade glioma patients can be significantly alleviated after symptomatic treatment, with good safety, which can effectively improve the cognitive function of patients, improve the quality of life of patients, and significantly extend the survival period of patients.