To calculate the temperature field on target surface conveniently during infrared imaging simulation, a method for calculating the radiation transfer coefficient on target surface based on accessible radiant energy is proposed. The formula method, Monte Carlo method, and accessible radiant energy calculation method are respectively used to calculate the radiation transfer coefficient between two vertical surfaces and that between two parallel surface models. The calculations are verified by simulation. The result shows that the calculation efficiency of the accessible radiant energy calculation method is improved greatly compared with the formula method and the Monte Carlo method, while its calculation accuracy is ensured to meet the requirements.