According to the structure and load characteristics of a pusher propeller equipped on a single engine airplane, the hazardous locations were determined based on finite element analysis. A telemetry system was designed and installed for strain measurement of the propeller blades. Flight test including different operating conditions was finished after test system installation. The variation rules of the vibratory stress with flight parameters were obtained. The results indicate that the static stress basically increases with altitude, air velocity and roll angle. However, at the altitude 5000m the variation trend of static stress with roll angle is not so clear. The dynamic stress increases with air velocity significantly, and with altitude and roll angle slowly. A resonance effect was discovered due to the close of the 1^st order dynamic frequency and the double rotor frequency in idle condition. Recommendation for the improvement of the resonance situation was provided as well.