In order to obtain the morphological feature images of different viscous droplets deformed and broken in high-speed airflow, the influence of viscosity in the process of deformation and fracture was quantitatively analyzed, and the high-speed camera direct shooting method was used to study the droplet deformation and crushing process in the horizontal shock tube. The characteristic parameters such as windward surface displacement, lateral deformation width, and crushing time were measured. Results showed that when the viscosity of the droplet was low, the shape of the trail formed by the tail of the droplet was an elongated pointed cone. When the viscosity of the droplet was high, the shape of the trail was corrugated, and the wake of the droplet was more complicated and disordered when the viscosity increased; the windward surface of the droplet was deformed and unstable under the action of the wave, and the "spike" structure was developed; the viscosity of the liquid hindered the deformation and fracture process; the lower viscosity of the drop led to the faster rate of development of Rayleigh-Taylor(RT) instability, and the number of "spikes" increased first and then decreased with the increase of viscosity.