In order to optimize the design of chili's Filling pipeline, taking solid-liquid multiphase fluid of chili as the research content, 90° horizontal bend model as the research object, calculating the suitable turbulence critical speed for the chili filling pipeline, using the mixture model of multiphase flow, the distribution of velocity field and density field was analyzed with inlet flow rate as 5, 7, 9 m/s. The results show that it is easy to form stratification when the speed is less than the critical speed. Geometric bend has large influence on multiphase flow field. The length of straight pipe section between the elbow and spout should not be too large. The results provide favorable data bases for filling conveyor speed setting in the oil pepper products filling equipment.