The invention discloses a method for treating heavy metal wastewater. The method comprises the following steps: (1) immobilizing mixed bacteria of pseudomonas pseudoalcaligenes and saccharomyces cerevisiae, collected after mixed fermentation culture, into immobilized cell spheres, wherein the appearances of the immobilized cell spheres are spherical, and the interiors of the immobilized cell spheres are of a porous mesh structure; (2) adding a rhizopus oryzae spore suspension liquid into starch bearing material hydrolysate as a culture medium at the pH of 3-6, carrying out shake cultivation for 24-48 hours, filtering to collect rhizopus oryzae mycelium spheres with the diameters of 50-100 microns; (3) filling a biological adsorber with the immobilized cell spheres and the rhizopus oryzae mycelium spheres, wherein the biological adsorber is formed by virtue of series connection of multiple adsorption columns; and (4) after regulating the initial heavy metal ion concentration of heavy metal wastewater to be less than or equal to 800mg/L and the pH value to be 5-7, enabling heavy metal wastewater to flow through the biological adsorber, wherein the hydraulic retention time in each adsorption column is 0.5h-1h. According to the method, different heavy metals (Cd<2+>, Hg<2+>, Cu<2+>, Zn<2+>, Ni<2+>, Ag<2+> and Pb<2+>) can be well adsorbed by virtue of different types of microbial live bacteria under different adsorption mechanisms.