Biosorption, with many advantages such as low-cost of sources, good adsorption effect, easily desorption, good recycling and being environmental-friendly, has been regarded as a cost-effective technology for heavy metals uptake at low metal concentrations. In this paper, the potentials and mechanisms of biosorption of lead ion, copper ion, cadmium ion, zinc ion and chromium ion in the single-ion aqueous solution using tartary buckwheat tea powders were investigated by spectral analysis. Scanning Electron Microscope (SEM), Energy Dispersive Spectrometer (EDS) and Fourier Transform Infrared Spectroscopy (FTIS) were used to characterize tartary buckwheat tea powders before and after the adsorption processes to identify the functional groups and elements which had changed, furthermore, to explore the possible mechanisms of the biosorption. The models of the adsorption isotherms (Langmuir, Freundlich, Temkin and Dubinin-Radushkevich) and the adsorption kinetics (pseudo-first order, pseudo-second order and intraparticle diffusion equation) were used to fit the adsorption behaviors. Response surface methodology is a collection of statistical and mathematical techniques based on fitting a polynomial equation to the experimental data. It can be well applied when a response or a set of responses of interest are affected by several factors. The response surface methodology was applied to evaluate the combined effects of various factors, namely initial metal ion concentration (A), adsorbent particle size (B), adsorbent dose (C) and contact time (D) on the removal rates of lead ion, copper ion, cadmium ion, zinc ion and chromium ion from aqueous solution using tartary buckwheat tea powders. The results of isotherm models indicated that the biosorption was mainly heterogeneous adsorption, accompanying other adsorption behaviors. The models of kinetic revealed that biosorption processes fitted a pseudo-second kinetic well, which suggests that the adsorption rates were controlled by effects of film diffusion and intraparticle process and the surface of tartary buckwheat tea powders changed into smoothed and melted. The lead ion, copper ion, cadmium ion, zinc ion and chromium ion onto surface of tartary buckwheat tea powders were confirmed by Energy Dispersive Spectrometer. The Fourier transform infrared spectra results exhibited that -OH, -CH2, -CH3, CO, -NH, -C-O, CH played major roles on removal lead ion, copper ion, cadmium ion, zinc ion and chromium ion using tartary buckwheat tea powders in single-ion aqueous solution. The results showed that the five values of the nonlinear models of coefficient constant were Adj R2Pb=97.10, Adj R2Cu=98.44, Adj R2Cd=94.55, Adj R2Zn=92.71 and Adj R2Cr=97.02, respectively for removal rates of lead ion, copper ion, cadmium ion, zinc ion and chromium ion in the aqueous solution using tartary buckwheat tea powders under conditions of various factors, which could navigate the design space for various factors on effects of biosorption the metal ions from aqueous solution. The effects of factors were in order as A＞D＞B＞C on removal rate lead ion, A＞C＞D＞B on removal rate copper ion, A＞B＞C＞D on removal rate cadmium ion, B＞C＞A＞D on removal rate zinc ion and C＞B＞D＞A on removal rate chromium ion, respectively by tartary buckwheat tea powders from single-ion aqueous solution. The study of results provided evidences that tartary buckwheat tea powders can be used for removing lead ion, copper ion, cadmium ion, zinc ion and chromium ion from single-ion aqueous solution.