Abstract: Airflow excitation has a major impact on the transient response of the flexible supported rotor. The physical process of the airflow disturbing rotor was analyzed, the Muszynska fluid excitation model was introduced, and then the differential equation of motion for the flexible supported rotor was established. The influence law of intake time and inlet pressure on the rotor transient response was obtained by numerical calculation. The results show that the longer intake time, the stronger influence of the airflow excitation force on the rotor transient response under the same inlet pressure. The critical intake time and critical inlet pressure were calculated. The applicability and correctness of theoretical models were verified by experiments.