The coal gasification fine slag has high porosity and large specific surface area, which can be used as an adsorption material, and the coal gasification wastewater with a high content of phenol and ammonia nitrogen can be reused in the mineral flotation process. In order to realize the resource utilization of coal gasification waste, flotation experiments were carried out in the clean water system and the simulated wastewater system to explore the effect of phenol and ammonia nitrogen on the flotation of coal gasification fine slag. The results showed that the flotation effect was optimal under the experimental conditions when the pulp concentration was 40g/L, the collector diesel content was 18kg/t，and the foaming agent MIBC was 12kg/t in the conventional clean water flotation system，and the flotation concentrate yield was 41.94%, the concentrate ash was 30.65%, and the flotation perfection index was 53.50%. In the simulated wastewater system, phenol and ammonia nitrogen were beneficial to promote the flotation of coal gasification fine slag, which was mainly because phenol could improve the collision and adhesion probability between coal gasification fine slag particles and collectors, and ammonia nitrogen was conducive to the selective capture of residual carbon components, thereby comprehensively improved the flotation effect. The flotation effect of coal gasification fine slag in the mixed solution with phenol concentration of 4000mg/L and ammonia nitrogen concentration of 5000mg/L was the best. Compared with conventional flotation, the flotation concentrate yield increased to 49.72%, the concentrate ash decreased to 28.74%, and the flotation perfection index increased by 13.91% to 67.41%.