Abstract: The biosorption-sedimentation process for removing the heavy metal cadmium from electroplating wastewater was experimentally investigated taking the waste Saccharomyces cerevisiae as biosorbent on a self-making experimental setup. The results showed that biosorption rate and removed rate of Cd are 96.59% and 94.25% respectively on conditions that wastewater processed is 1L, Cd concentration in the wastewater about 26mg/L, pH value 7.0, the dose of the waste Saccharomyces cerevisiae 40g/L(in wet weight), at room temperature about 25°C, stiring speed 1000rpm, adsorbing time 30min and time for natural sedimentation 240min. The Cd concentration in wastewater after three-step biosorption comes up to china's national standard on effluents(&le0.1mg/L). With respect to the processing effect, the continuous process is relatively poorer than the intermittant one. The biosorption mechanism of the water-washing process with waste Saccharomyces cerevisiae for Cd removal was analyzed by SEM and EDS. The results showed that the cell structure of the bacteria used is destroyed in such a water-washing process, and the effects of chemical complexing and electrostatic adsorption are found in the biosorption process.