Background <p>Poststroke cognitive impairment (PSCI) significantly reduces quality of life and survival rates. Current interventions face challenges in efficacy and accessibility. Noninvasive brain-computer interface (BCI) technology may enhance neural plasticity and cognitive recovery through real-time neurofeedback, offering a safe and accessible approach for poststroke cognitive rehabilitation. This trial aims to evaluate the efficacy of BCI-based cognitive training and explore its neural mechanisms.</p> Methods <p>A prospective, randomized, double-blind, controlled, single-center trial will enroll 66 PSCI patients. Participants will be randomized into the intervention group or control group. Interventions will be administered 5 days/week for 4 weeks. Primary outcome is as follows: The 4-week post-intervention MoCA scores; secondary outcomes are as follows: 3-month follow-up MoCA scores, attention, memory, executive function, neurophysiological markers, and daily living function. Assessments will be conducted at baseline (<i>T</i>_0W), post-intervention (<i>T</i>_4W), and 3-month follow-up (<i>T</i>_16W).</p> Discussion <p>Results will provide evidence for BCI’s clinical utility and neuroplasticity mechanisms, guiding personalized neurorehabilitation strategies.</p> Trial status <p>The protocol version used for this study is Version 3.0, dated May 8, 2025. Recruitment is scheduled to begin on June 10, 2025, and is expected to be completed by May 8, 2026.</p> Trial registration <p>Chinese Clinical Trial Registry ChiCTR2500107318. Registered on 8 August 2025.</p>