Heavy metal contamination stemming from industrial waste is an increasingly grave issue with extensive repercussions for human health and the ecological environment. Biochar demonstrates significant potential in remedying heavy metal pollution; however, the effectiveness of raw biochar is constrained under low pH and high heavy metal concentrations. To address this challenge effectively, this study utilized dragon fruit peels as precursors to produce biochar through pyrolysis at 500 °C for 2 hours. An efficient green adsorbent, termed GBMSs (green biochar-metakaolin-sodium silicate), was developed. Response surface methodology (RSM) tests revealed that GBMSs exhibited exceptional adsorption performance for zinc, achieving up to 67.37 mg/L at pH=2. Kinetic and isothermal adsorption studies indicated that the adsorption process of GBMSs on Cu and Zn closely followed the Langmuir model and the pseudo-second-order kinetic equation, suggesting surface adsorption of a homogeneous monomolecular layer with a rapid adsorption rate that increased with rising pH. In-depth analysis using XRD and SEM-EDS techniques identified chemisorption as the primary adsorption mechanism, with ion exchange, surface complexation, and co-precipitation playing significant roles. These findings confirm that GBMSs, as an environmentally friendly and efficient adsorbent, holds considerable promise for the treatment of heavy metal pollution.