Objective To systematically review the rehabilitation effect of isokinetic muscle training on knee muscle strength, functional walking ability and dynamic balance in post-stroke patients. Methods PubMed, Ovid Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, Chongqing VIP, and Wanfang databases were searched online for randomized controlled trials on isokinetic muscle training of lower limbs in post-stroke patients. The retrieval time was from inception to October, 2022. Endnote X9 software was used to manage the literature. Cochrane Manual 5.1.0 was used for quality assessment, and RevMan 5.4 software was used for meta-analysis. Results A total of 20 randomized controlled trials were included in the study, with the intervention group using isokinetic muscle training of the lower extremities or combined with conventional rehabilitation training and the control group using conventional rehabilitation training and/or other intervention, with a total of 1448 study subjects. Meta-analysis results showed that the differences in knee flexion peak torque [mean difference (MD)=5.85 N·m, 95% confidence interval (CI) (4.84, 6.85) N·m, P<0.00001], knee extension peak torque [MD=9.09 N·m, 95%CI (4.83, 13.36) N·m, P<0.0001], Time Up Go test [MD=–4.70 s, 95%CI (–6.68, –2.72) s, P<0.00001], 10-meter walking test [MD=–4.71 s, 95%CI (–9.12, –0.31) s, P=0.04], Fugl-Meyer Lower Extremity Motor Function Assessment score [MD=6.61, 95%CI (3.52, 9.70), P<0.0001], and Berg Balance Scale score [MD=5.61, 95%CI (0.91, 10.31), P=0.02] were statistically significant. Conclusion Isokinetic training may improve knee strength and functional walking ability in post-stroke patients, but there is still no strong evidence of improvement in motor function and balance.