[Objective] To compare the effects of three local injection analgesics formulations used in total knee arthroplasty（TKA）. [Methods] 230 patients undergoing unilateral primary TKA were observed continuously. Three formulations of local injection of analgesic drugs were observed, and the effects of the three formulations on postoperative pain and range of motion were compared. [Results] Patients taking compounded betamethasone had lower postoperative pain score (0.76±0.76 vs 1.10±0.95 at 28 days postoperatively, P=0.01) and lower frequency of opioid use (2.35±4.58 vs 7.18±4.58, P<0.001) than those treated with epinephrine, and the incidence of opioid adverse reactions were also lower (37/167 vs 32/50, P<0.001), there was no significant difference in postoperative pain among patients with different doses of ropivacaine (P>0.05). There were no significant differences in operative duration, drainage volume, blood loss and range of motion among all groups (P>0.05). [Conclusion] Compared with ropivacaine + epinephrine, ropivacaine + compound betamethasone in analgesic formulations can better reduce postoperative pain in patients undergoing TKA.