Cr, Ag co-doped wurtzite ZnS nanomaterials were prepared by hydrothermal method, and the effects about different reaction time and different doping ratio of Cr and Ag on optical property of ZnS nanomaterials were investigated. The optical performance and structure of Cr, Ag co-doped ZnS materials were characterized respectively by fluorescence spectrophotometer, infrared spectrometer, X-ray differaction (XRD), and scanning electron microscope (SEM), and the adsorption performance for four kinds of reactive dyes such as methyl violet (MV), butylrhodamine B (BRB), tetrachlorotetrabromo fluorescein (TCTBF) and eosin B (EB) was discussed further. The results showed that Cr3+ and Ag+ replaced and embeded into the location of Zn2+, and doped into the crystal lattice of ZnS. Thus the optical property and morphology of doped ZnS nanomaterials changed according to the optical characterization and SEM. That is to say, after being doped into Cr and Ag, the fluorescence intensity of ZnS was reduced, moreover, it has normal shape, puffy surface and pompon-like structure. And the morphology and the optical property of doped ZnS nanomaterials were optimum as 12 h of the reaction time, and doping proportion of Cr and Ag were respectively 1%. According to the N2 isothermal adsorption-desorption analysis, the specific surface area and pore size distribution of Cr, Ag co-doped ZnS materials were calculated. Meanwhile, the doped ZnS materials were used to adsorb MV, BRB, TCTBF and EB respectively. And the influence of doped ZnS materials on adsorptivity for several reactive dyes were inspected from the factors such as adsorption time, temperature and pH value respectively. Then the maximum adsorption quantity of Cr, Ag co-doped ZnS materials for four reactive dyes was obtained under the conditions about 7 of pH value and 9, 11, 9 and 9 h of absorption separately at room temperature.