〔Abstract〕 Objective To investigate the effect of high-precision transcranial direct current stimulation(HD-tDCS) on cognitive and social functions in convalescent schizophrenics. Methods 100 cases of convalescent schizophrenics admitted to our hospital from January 2018 to June 2019 were selected as the research objects. According to the random number table method, they were divided into two groups, and 50 cases in each group. Both groups used HD-tDCS to stimulate the left dorsolateral prefrontal lobe on the basis of conventional psychiatric treatment. The real stimulation group used 1.5 mA current stimulation for 20 min, and the false stimulation group only used 30 s passing at the beginning and end of stimulation, both once a day, lasting for 10 days. The social function and cognitive function of the two groups were assessed by the inpatient psychiatric social function assessment scale(SSPI) and the Chinese version of the matrix cognitive battery(MCCB) before and end of the treatment, and the adverse reactions of the two groups in HD-tDCS treatment were compared. Results There was no significant difference in the total score of SSPI and MCCB between the two groups before and after treatment(P>0.05); After treatment, the total score of SSPI and all factors in the two groups were higher than those before treatment(P<0.05), and the total score of SSPI and all factors in the real stimulation group were higher than those in the false stimulation group(P<0.05); After treatment, the total score of MCCB, information processing speed, attention/alarm in the real stimulation group were higher than those in the real stimulation group(P<0.05) The scores of perception, working memory, reasoning and problem solving were higher than those before treatment(P<0.05). The patients in both groups were well tolerated to electrical stimulation or false stimulation, and there was no serious adverse event and no significant difference between the two groups(P<0.05). Conclusion HD-tDCS treatment for convalescent schizophrenics is beneficial to promote cognitive rehabilitation and further improve social function, which has a good application prospect.