Abstract: The ore of Anhui Tongguan Lujiang Mining Co., Ltd. is a complex gold-bearing copper sulfur ore, which contains various useful metal elements such as copper, gold and sulfur. The original design of the copper sulfur ore flotation process uses lime as a depressant for pyrite, and a large amount of lime is added in the roughing and cleaning operations to form a highly alkaline pulp environment to achieve copper sulfur separation. Through a year of production practice, it has been proven that the process has high reagent consumption, poor flotation indicators, and low gold recovery. The comprehensive production cost is high. To address this issue, researchers conducted a detailed process mineralogical study of the copper sulfur ore, analyzing the characteristics of the ore and the occurrence state of gold. Through practical exploration such as small-scale experiments and industrial experiments, the original process flow is changed to adopt the principle of low alkalinity copper sulfur mixed flotation process. The roughing and sweeping operations are changed to low alkalinity flotation, with the pH value maintains between 7-9, and the high alkalinity still maintains during the cleaning process to achieve copper sulfur separation. After three years of practice, local low alkalinity flotation has achieved good economic and social benefits. The copper recovery rate has increased by more than 2%, the gold recovery rate has increased by more than 9%, and the silver recovery rate has increased by more than 7%. At the same time, using low alkalinity flotation also saves lime consumption, reduces the frequency of pipe plugging, and stabilizes the production process.