Transcranial direct current stimulation (tDCS) and transcutaneous electrical nerve stimulation (TENS) are both recognized for their analgesic effects; however, evidence suggests limitations in their efficacy when applied to knee osteoarthritis (KOA) after stroke. This study aimed to assess the efficacy and cortical activity impact of a dual-target electrical stimulation approach combining tDCS and TENS in the treatment of KOA after stroke. We hypothesized that the combination of tDCS with TENS could more effectively address KOA after stroke by enhancing brain activity through the induction of neural oscillations. To test this hypothesis, a double-blind, randomized trial was conducted with 30 participants receiving either TENS + tDCS or TENS + sham tDCS over an 8-week period, from Monday to Friday. Electroencephalograms (EEGs), Brief Pain Inventory (BPI), visual analog scale (VAS), stride length, cadence, 6-min walk test (6 MWT), knee range of motion (ROM), and quadriceps strength were collected pre- and poststimulation. Pain indicators were analyzed using -tests for continuous variables and chi-square tests for categorical variables, with repeated measures ANOVA employed to explore changes and interactions over time. For EEG analysis, paired -tests were utilized to investigate changes in brain regions before and after treatment on the affected side, with visual analysis conducted subsequently. The results indicated that the combined treatment led to significant improvements in the affected hemisphere, with significant changes observed in α1, α2, and β power. Additionally, significant group× time interaction effects were noted for BPI, VAS, stride length, cadence, and 6MWT. The study concludes that dual-target electrostimulation using tDCS combined with TENS significantly ameliorates knee joint inflammation following stroke by acting on the cerebral cortex and target organs. Chinese Clinical Trial Registry: ChiCTR2200064735.