This work carried out liquid–solid two-phase jet experiments and simulations to study the erosion behavior of 304 stainless steel at 30° impingement. The single-phase impinging jet was simulated using dense grid by one-way coupling of solid phase due to its dilute distribution. The simulation results agreed well with experiments. It was found that after impinging particle attrition occurred and particles became round with decreasing length-ratio and particle breakage occurred along the “long” direction. Both experiment and simulations found that the erosion generated on the sample could be divided into three regions that were nominated as stagnant region, cutting transition region and wall jet region. Most particle–wall impacts were found to occur in the cutting transition region and the wall jet region. In the cutting transition region, holes and lip-shaped hogbacks were generated in the same direction as the flow imping. In the wall jet region, furrows and grooves were generated. The averaged grooves depth tended to become constant with the progress of impinging and reach the steady state of erosion in the end. In addition, it was found that impinging effect increased erosion and anti-wear rate.