Chronic copper intoxication via drinking water induces diseases and physiological toxicity. Bamboo charcoal has been applied in the treatment of copper (Cu2+) in water. However, the adsorption by micron bamboo charcoal (MBC) of trace Cu2+ in tap drinking water and the underlying factors behind it have not been sufficiently reported. In this study, to improve the adsorption by MBC of trace levels of Cu2+ in drinking water, MBC was thermo-modified and characterized. Through batch experiments, the adsorption equilibrium was analyzed, and isotherm models were simulated. The removal rates and the optimization were investigated through a general full factorial design including the thermo-modified temperature (MT), initial concentration (C0), and dosage. The results indicated that the thermo-modification significantly improved the removal by MBC of Cu2+ at trace level C0. The satisfactorily low level of 0.12 ± 0.01 mg⋅L−1 was achieved in the range of C0 from 0.5 to 2.0 mg⋅L−1 within the short contact time of 0.5 h. The processes conformed to the Freundlich and Langmuir adsorption isothermal models at a C0 lower than 4.0 mg⋅L−1 and higher than 8.0 mg⋅L−1. The correlation between C0 and dosage played an important role in the removal of Cu2+. This work proposes the application of the ecofriendly material MBC and an optimization mode in the removal of trace Cu2+ from tap drinking water. It is also revealed that the positive and negative correlation and the “critical point” of the removal rate with dosage depend on the initial concentrations.