Biochar with developed pore structure was prepared by using high?humidity Chinese herbal medicine wastes (CHMWs) as raw material, using the water vapor generated by its own water under a high temperature environment for physical activation，and the effects of moisture content, activation temperature and activation time on the performance of biochar were investigated. The performance of biochar was analyzed by physical adsorption instrument, Fourier transform infrared spectroscopy, scanning electron microscopy and other instruments, and the optimal reaction conditions for biochar preparation were obtained, and the activation mechanism of biochar prepared from CHMWs was discussed. The prepared biochar was used to adsorb wastewater containing Cd²⁺ and Cu²⁺, and the adsorption kinetics were discussed. The experimental results showed that under the conditions of 700 ℃ heating temperature, 60 min heating time and 50% moisture content of the CHMWs, the biochar with a specific surface area of 309.29 m²/g and a pore volume of 0.116 8 cm³/g and was obtained. The experimental results of adsorption showed that the adsorption kinetics on Cu²⁺and Cd²⁺ conformed to the quasi second order kinetic equation, and the optimal adsorption capacities of Cu²⁺ and Cd²⁺ were 20.66 mg/g and 17.41 mg/g respectively.