The invention discloses a method for achieving flotation of gold-containing ores through a biological agent. Flotation is performed through the steps of ore grinding, roughing, concentrating and scavenging. Ore grinding comprises the steps that raw ores are ground until the particle size is smaller than 0.074 mm and the content is larger than 70%, the concentration of ore slurry obtained through ore grinding is regulated to be 33%, stirring is performed for 2-3 minutes, a collecting agent and a foaming agent are sequentially added while stirring is performed, and the collecting agent is prepared from xanthate and the biological agent; the collecting agent is prepared by cooperatively using the xanthate and the biological agent, and therefore the gold flotation recycling rate and the concentrate grade can be effectively increased; the adopted biological agent is green and environmentally friendly and can be naturally degraded, therefore, the wastewater treatment link is omitted, and the production cost is reduced.