After studying the factors of how the slit width of a slitted bluff-body (SBB) burner influences the cold state flow field, the hot state temperature and gas concentration fields, the following important conclusions are obtained: the slit width influences not only flow characteristics behind the slitted bluff-body such as the size and reflux rate of the recirculation region, but also the quantity of pulverized coal jetting into it. To use it in an industrial plant, the optimal value of slit width is determined as about 10 percents of the width of the bluff-body (BB).