The mechanism of blood embolism formation always attracts the attention of researchers. Through calculating rigid particle movement in a bifurcated pipe, the blood flow as well as blood embolism in a bifurcated pipe are simulated preliminarily, and the flow speed and the probability to form thrombus are investigated. We can draw a conclusion that the higher the hematocrit is, the easier the blood is to form embolism, meanwhile, the bigger the pressure difference, the harder the blood is to form embolism. We also find that the embolism tends to occur at the entrance of a bifurcated pipe and bifurcation forming place. Beyond the bifurcation place, the hematocrit of the blood in a big tube is larger than that in a small tube.