Highpressure steam injection method is the major method of exploitation of heavy oil reservoir. In steam injection pipe network, the fluid in steam, liquid and solid phases scoured the bend and led to leakage. Based on the turbulence models, multiphase flow models, discrete phase models and erosion models ,and considering the mutual coupling of the different phases, the numerical simulation of the flow of the three phases in the bend flow was established. The results show that in the steam injection pipelines，as bending degree of the bent pipe increased， the distribution and wall wear area of the liquid phases and particle phases moved backwards step by step，and the value increased accordingly. Moreover, the increase of liquidphase volume fraction in the pipe wall could effectively reduce the surface corrosion of the solid phase.