Abstract: With the incessant improvement of environmental requirements, selective catalytic reduction（SCR） flue gas denitration systems are widely used for power plants. For the large delay and great inertia of SCR system, combining mechanism model of SCR and feedforward control method, employing sliding window method to update model parameters and adjust feedback coefficient in time, self-adaptive intelligent feedforward control method was proposed. Actual operation data was applied to verify the method based on simulation experiment. The results show that comparing with traditional PID control method, this method achieves the accurate and timely control of the amount of ammonia and improves the denitration rate as well as avoids excessive ammonia injection.