Non-Newtonian fluid model is introduced into multiphase LBM to investigate non-Newtonian fluid displacement in porous media. To begin with,process of a Newtonian fluid displaced by pseudo-plastic fluid and Newtonian fluid in a simple pore with a small obstacle is studied. It shows that fluid displaced by pseudo-plastic fluid is faster than that by Newtonian fluid. Besides,interface tension effects on displacement process is investigated in detail. It indicates that interface tension plays a resistant role during displacement process. Lower interface tension enhances displacement. By using quartet structure generation set (QSGS) algorithm,we perform a series of modeling of displacement in porous media systems. Impacts of interface tension,wettability and pressure difference on final production are discussed.