Green and low-carbon is the requirement of today's development. Airlines can take the optimization of aircraft scheduling as a breakthrough to reduce carbon emissions. In order to calculate the planned carbon emissions of multiple flights,International Civil Aviation Organization （ICAO） carbon emission calculation formula is adopted. For two types of aircraft, A320 and B737, with the minimum carbon emissions as the constraint condition, CPLEX software is used to find the optimal solution of the aircraft on a certain flight segment, and ultimately achieve the minimum carbon emissions of the whole flight segment. The results show that the use of two hybrid aircraft types on the leg can save more carbon emissions than the use of a single aircraft type, and reduction range of carbon emissions is between 0.6% and 2.9%, which proved the rationality of optimizing airline models based on carbon emissions.