The work aims to study erosive wear law of oil and gas well pipe column or ground oil and gas pipeline materials under the effects of solid particles. The particle model was extracted according to shape characteristics of quartz sand particles, and impact wear dynamic behavior of solid particles on 20# steel was studied in finite element method. Impact stress characteristics and material accumulation form of quartz sand particles were analyzed at different impact angles, different particle sizes and different impact velocities. Provided with given parameters, the maximum equivalent stress first increased and then decreased as the impact angle in-creased, and reached the maximum 1370 MPa at 40°. In case of high-angle erosion, erosion morphology was manifested by chisel pit and plastic extrusion, while in case of low-angle erosion, erosion morphology was dominated by micro-cutting and furrow-shaped lip. The material was accumulated on both sides and the front end of erosion pit, and height of deformed lip in the front of erosion pit gradually increased, and reached the maximum 0.019 85 mm at 40°. As the impact velocity increased, the maximum equivalent stress increased monotonously, and depth of impact pits changed slightly. However, accumulated materials in the front of impact particles increased significantly, and height of deformation lip increased. When the particle size was below 0.15 mm, the maximum equivalent stress increased with the increase of particle size, and reached the maximum value of 1410 MPa at the particle size of 0.15 mm. As the particle diameter exceeded 0.15 mm, the maximum equivalent stress decreased with the increase of particle size. With the increase of particle size, depth of erosion pit increased slowly, and height of deformation lip in the front of particle increased significantly. Dynamic behavior of 20# steel under the impact of quartz sand is successfully simulated in finite element method, law of effects of impact angle, impact velocity and particle size on stress distribution and erosion morphology during the impact process of 20# steel is obtained.