The flutter stability of long-span suspensions bridges during erection can be more problematic than in the final state. The characteristics of the flutter stability during construction are influenced by many factors such as the sequence of deck erection. In this paper, numerical flutter stability analyses are performed for the construction process of the Zhongdu Bridge over Yangtze River using the commercial FE package ANSYS. The effect of stiffness reduction of stiffening girder, structural damping, the initial wind attack angle, and the sequence of deck erection are discussed in detail. It is found that the non-symmetrical sequence deck erection is confirmed to be aerodynamically favorable for the deck erection of long-span suspension bridges and the best erection sequence should be investigated in the design phase. The initial wind attack angle of -3 degrees is advantageous for the aerodynamic stability, but initial wind attack angle of +3 degrees is disadvantageous comparing with the initial wind attack angle of 0 degrees during the deck erection. The stiffness reduction of the stiffening girder has slightly effect on the flutter wind speed of the suspension bridge during erection, but structural damping has a great impact on it, especially for the early erection stages.