When a helicopter flies in sand and dust environment or encounters sandy weather, the sand entering the engine compressor can cause severe erosion damage to the blades. This paper aims to deduce an erosion rate prediction model for titanium alloy blade material which can take into account the probability factors such as particle size, velocity and sand fracture. Methods to judge whether sand fractured and quantify the effect of sand fragmentation on erosion damage were obtained. The probability relationship between particle size and mass ratio, impact kinetic energy and fracture rate, particle size range and impact velocity were studied. It is verified that the model can not only adapt to the high-speed erosion conditions, but also adapt to the probability characteristics of many impact factors. The angle of maximum erosion rate under relative high-speed erosion condition is significantly larger than that of under relatively low-speed erosion condition. (C) 2020 Elsevier B.V. All rights reserved.