Abstract: Study on the impact dynamics of particles Is of great significance for understanding the adhesion and rebound mechanisms of the particles. Using Particle Shadow Velocimetry (PSV), a dynamic testing platform was constructed for single-particle impacting on the wall under high-temperature conditions, along with a MATLAB-based image processing tool for particle analysis. To address the challenge of measuring particle diameter in this experiment, a sub-pixel interpolation and maximum inscribed circle method was introduced and validated. The study indicated that the Otsu threshold segmentation algorithm performed better in measuring particle diameters, and while sub-pixel methods and interpolation factors significantly affect results with a notable window effect. Particle restitution coefficients decreased with impact velocity, and flow field impacts needed to be considered. This study deepens the knowledge of single-particle impacts and paves the way for the complex multiparticle system research.