In order to study the impact of blind pipes in the oil contamination of product oil stations, the paper first gave the summary, definition and classification for typical blind pipe, then use the commercial CFD software CFX to make numerical simulation and conduct related experiment. The oil replacement process achieved from numerical simulation was compared with the experiment. The results showed a high degree of agreement. Then the oil replacement rules of straight blind pipe, bend blind pipe and L-shaped blind pipe were carried on by CFX numerical simulation. The results showed that L-shaped blind pipe had the greatest influence on the oil quality and longest replaced time, followed by bend blind pipe, and straight blind pipe was the least. We do the numerical simulation to obtain oil replacement rate, contaminated oil concentration and rules of oil replacement under different blind pipe length, oil velocity, and the structure of blind pipes. The research can provide a basis for construction, process modification and equipment layout of product oil stations, and improve the operation efficiency and economic benefit of product pipeline.