Objective To explore the effects of different doses of valproate on serum thyroxine （TSH）， prolactin（PRL）and dopamine （DA） in patients with bipolar disorder （BPD） level of influence. Methods A total of 90 patients with BPD who received treatment in hospital from May 2020 to May 2022 were selected as the study objects. They were randomly divided into groups A， B and C， with 30 cases in all. Groups A， B and C were orally administered 10 mg/kg， 15 mg/kg and 20 mg/kg sodium valproate every day， respectively. The clinical efficacy， scores of mental diseases before and after treatment， indexes related to blood drug concentration， serum levels before and after treatment， indexes related to liver function and incidence of adverse reactions were compared among the three groups. Results There was no significant difference in the total effective rate among the three groups after treatment （P > 0.05）. After treatment， the scores of the three groups were significantly improved compared with before treatment （P < 0.05）. There was significant difference in the time to reach the stable state serum concentration （P < 0.05）. There were no significant differences in TSH， PRL and DA levels among the three groups after treatment compared with before treatment （P > 0.05）. ALT and AST levels in the three groups after treatment were increased compared with those before treatment （P < 0.05）， and there were statistically significant differences in ALT and AST levels among the three groups after treatment （P < 0.05）. There was significant difference in the incidence of adverse reactions among the three groups （P < 0.05）. Conclusion Sodium valproate can effectively treat BPD patients and relieve the degree of mania or depression， but has no significant effect on the level of TSH， PRL and DA. Among them， small dose of sodium valproate can guarantee the therapeutic effect and have less impact on liver function， and less adverse reactions， high safety， worthy of clinical promotion.