Precision fertilization is the key direction of agricultural green development. Slow/controlled release fertilizer provides nutrition for plants at a pace that is compatible with their needs, to minimize nutrient loss and environmental risk. Solventless polyurethane coating material is an important branch in the current research of slow/controlled release fertilizer. In order to better grasp the research status and development trend, the progress in these aspects, such as synthesis technologies, product types and modification methods is analyzed, compared and summarized from the point of view of material synthesis. The analysis results show that different kinds of biomass raw materials have been applied in the synthesis of coating, which enrich the source and variety of coatings. Filling, interpenetrating polymer network and organosilicon are effective modification methods for coating materials. It is pointed out that simple and efficient modification method with low cost, clear controlled release mechanism and performance control, green and environmental protection, functional and industrialization of membrane materials are the main trends of solventless polyurethane envelop research in the future.