Boeing 737~800 was selected as a typical model in this thesis. Based on BM2-FOA coupling model, PM_2.5 emission indices in full thrust and reduced thrust takeoff from the takeoff time to the height of 1000m were obtained through aircraft performance parameters simulation, and emission loads were worked out then. At the same time, the influences of sulfur content on emission levels were presented, and then the contributions to PM_2.5 emissions from different components were calculated. A comparison was made between the results using coupling model and ICAO standard parameters. The result showed that the differences of PM_2.5 emission indices were mainly during the period of takeoff on the ground before climbout. The PM_2.5 emission of a full thrust takeoff is the largest which the amount is 37.6g (low-sulfur fuel), because of the highest emission indices of non-volatile and volatile organic PM_2.5 components. In terms of reduced thrust processes, PM_2.5 emissions decreased to 36.7~35.5g. PM_2.5 emissions increased by 150% when high-sulfur fuel is used. It has been found from the comparison that the emissions calculated by ICAO standard parameters lead to relatively large errors. Compared with the light-duty gasoline vehicle (national Ⅳ standard), the PM_2.5 emissions of one full thrust takeoff with low-sulfur fuel and high-sulfur fuel equal the emissions of running 2984km and 7294km respectively. Accurate calculation method is supposed be the basis for the preparation of aircraft emission inventory in the airport area.