Abstract: There are quite different views on the motivation of anti-Semite of Crusades in medieval Europe.As the dominant factor,Christian anti-Semitism consciousness promoted the centuries-long persistence of anti-Semitic activities,the strong religious atmosphere provided a suitable "soil" of fanatical anti-Semitic violence,and the economy pressure became a breakthrough on anti-Semite.Many factors contributed to Europe's frequent anti-Semitic activities.