This is a multi-center, prospective, open-label randomized controlled trial evaluating the efficacy and safety of virtual reality-based mindfulness-based cognitive therapy (VR-MBCT) as an adjunct to usual care in adults with chronic nonspecific low back pain (CNLBP). A total of 214 participants aged 20-70 years with pain duration ≥3 months and average back pain bothersomeness ≥4 (0-10 scale) will be enrolled from three hospitals in China and randomized 1:1 to an 8-week VR-MBCT intervention group or a waitlist usual care control group. The co-primary outcomes are the proportions of patients achieving ≥30% improvement from baseline in Oswestry Disability Index (ODI) and self-rated back pain bothersomeness at week 8. Secondary outcomes include pain intensity (NRS), global improvement, anxiety (GAD-7), depression (PHQ-9), physical activity (IPAQ-SF), sleep quality (SQS), fear-avoidance beliefs (FABQ-PA), pain catastrophizing (PCS), work productivity (WPAI-GH), treatment use, system usability (SUS), and patient satisfaction. Safety will be monitored for VR-related adverse events. Assessments will be performed at baseline (T0), week 4 (T1), week 8 (T2), and week 26 (T3). Data will be analyzed following the intention-to-treat principle using mixed-effects models and per-protocol analyses.