The invention relates to a sintering desulfurization and main exhaust fan joint control method which belongs to the technical field of joint control of a sintering main exhaust fan and a desulfurization fan, in particular to a method for controlling the valve opening of the main exhaust fan and the valve opening of the desulfurization fan automatically based on total sintering material amount change, desulfurization fan current change and desulfurization tower negative pressure value change. The method comprises two control modes according to increase and decrease situations of the total material amount of a sintering machine: 1), when the total material amount is increased, relevant operation on a main exhaust valve is increased; and 2), when the total material amount is decreased, the relevant operation on the main exhaust valve is decreased. The valve opening of the desulfurization fan is automatically adjusted in the two modes according to specific conditions. By implementing the sintering desulfurization and main exhaust fan joint control method, the automatic control level of the main exhaust fan and the desulfurization fan is greatly improved during a sintering production process; joint operation and joint adjustment on the main exhaust fan and the desulfurization fan are realized; stability of a desulfurization tower negative pressure value is ensured, and positive pressure and other dangerous conditions are avoided; and the effect of flue gas desulfurization is also improved.