Heavy metal wastewater is treated through the synergy of multiple groups of biological agents to form stable heavy metal complexes. The pH value is adjusted with alkali for hydrolysis reaction. Since the biological agents also have efficient flocculation effect, when the heavy metal complexes hydrolyze to form particles, they quickly flocculate to form micelles, achieving simultaneous efficient purification of multiple heavy metal ions (arsenic, cadmium, chromium, lead, mercury, copper, zinc, etc.)