This study aimed to investigate the effects of exoskeleton robot-assisted sit-to-stand training on balance, lower limb motor function, and Activities of daily living (ADL) in hemiplegic stroke patients, evaluated via cortico-muscular coherence (CMC) analysis. Forty-eight patients were randomized into an exoskeleton group and a control group. Both groups received conventional rehabilitation therapy. The exoskeleton group underwent exoskeleton-assisted sit-to-stand transfer training in addition to conventional therapy, while the control group received traditional lower limb rehabilitation training. After 3 weeks of intervention (5 days/week, 30 min/session), both groups showed significant improvements in Berg Balance Scale (BBS), Fugl-Meyer Assessment - Lower Extremity (FMA-LE), and Modified Barthel Index (MBI) scores (P < 0.05). The exoskeleton group demonstrated greater improvements in BBS and MBI (P < 0.05), with no significant difference in FMA-LE. CMC analysis revealed notable post-intervention increases in β (13–30 Hz) and γ (>30 Hz) bands for both groups, with more pronounced improvements in the exoskeleton group (P < 0.05). These findings indicate exoskeleton robot-assisted training outperforms conventional rehabilitation in enhancing balance and ADL, likely by improving CMC during sit-to-stand tasks.