In order to study the influence of the simulated pulsating wind field with the traditional exponential decay coefficient Cy on the buffeting response of long-span suspension bridges， frequency and time domain methods were first applied for buffeting response analysis taking three long-span suspension bridges ranging from 1 000 m to 2 000 m as the background. The results indicate that the buffet response from the time domain method， considering factors like wind load nonlinearity， is safer. Based on the time domain method， reponsesat the different spanwise position of the suspension bridge under different Cy values was analyzed. The buffet response was compared with the buffet response when Cy=16 recommended by Davenport. The results show that the buffet response of the suspension bridge does not simply change linearly with the change of Cy. The buffet displacement RMS value of the three suspension bridges at the mid-span position always remains the largest under different values of Cy； When Cy is 14， the maximum values of the vertical， lateral and torsional angular displacement response RMS values of the suspension bridge are larger than those when Cy=16， which are 1.5%， 14.6% and 26.3%， respectively. The results of the buffeting response analysis of large-span suspension bridges using Davenport’s recommended values are dangerous. When performing the most unfavorable buffeting response analysis， it is recommended to select multiple groups of Cy values for calculation.