Solid particle erosion-wear behavior under different working conditions was simulated by FEM. A three-dimensional finite element model of erosion-wear of solid particle was established, and Johnson-Cook material model and failure criterion were adopted to define the mechanical property of sample material. The process of spherical particle impacting 45 steel from different angles and under different impact velocity was simulated, respectively. Material deformation and strain condition were analyzed .The relationship between erosion-wear degree , impact angle and impact velocity was investigated. The results showed that, maximum plastic strain occurs on the surface of material when impacting from low angle and on subsurface while vertical impacting. The wear degree of material increases until reach the peak value at 40° and deformation volume increases with the vertical impact velocity，and there is significant accumulation of material around pit.