Starting from the normal vector of wavelet planes of the sea surface,the morphology of sea surface was simulated by the ocean wave spectrum model. A new and simple algorithm was put forward,each wavelet plane of sea surface is divided into two triangular facets,and the normal vector of triangular facet is determined to calculate the emissivity of sea surface,which can greatly reduce the computation difficulty. Then,considering the thermal self-radiation of sea surface,the radiation that the sea surface reflects the sky and the sun,and the atmospheric path radiation between the sensor and the sea surface,the infrared radiation model of sea surface was established. Finally,the gray image of the infrared radiation of sea surface was generated,and the simulation results are given under the different zenith angles. The simulation results show that the method can effectively simulate the infrared radiation characteristics of sea surface,and the simulated infrared images are very important for ship infrared image simulation and infrared detection.