A fertilizer plant wastewater recycling as a research object, the establishment of ORC (Organic Rankine Cycle, referred to as ORC) cogeneration system, using MATLAB software to simulate the operation of the system was found to change the evaporation temperature, condensing temperature, superheat and subcooling degree of the four factors will have an impact on the performance of the system, in which the evaporation temperature and degree of superheat to improve the performance of the system, the condensing temperature and degree of subcooling have a negative effect on the system efficiency. The evaporation temperature and superheat are favorable factors for improving the system performance, while the condensation temperature and subcooling degree adversely affect the system efficiency. Through the verification calculation of specific working conditions, under the conditions of evaporating temperature 110℃, condensing temperature 27℃, superheating degree 8℃ and subcooling degree 3℃, the thermal efficiency of the system can reach about 25%, and the energy efficiency reaches about 45%. The experimental results show that this designed ORC cogeneration system is able to recycle industrial waste heat to a greater extent, which is of great significance to improve the efficiency of energy utilization.