The invention belongs to the technical field of material preparation and photocatalytic environmental pollution control and particularly relates to a nickel sulfide hollow microsphere/carbon nitride composite photocatalyst preparation method. By a simple one-step hydrothermal method, graphite type carbon nitride modified regular micron nickel sulfide hollow microsphere photocatalyst is obtained. According to a photocatalytic degradation Rhodamine B experiment, the prepared catalyst is high in photocatalytic activity and environment stability. All adopted raw materials are free of pollution, the method is convenient and simple in process and low in preparation cost, the obtained catalyst is high in practicality, and easiness for large-scale production and high economic benefits and environmental production benefits are achieved.