Experimental studies on the solids holdup of a high-flux circulating fluidized bed (HFCFB) at an operating pressure up to 0.5?MPa were carried out. The effects of operating pressure, solids mass flux and superficial gas velocity on the solids holdup distribution were systematically tested. It was found that the solids holdup at elevated pressure increases with increasing solids mass flux but decreases with increasing superficial gas velocity, which is similar to the trends at atmospheric condition. As a result, the condition of a high-density circulating fluidized bed (HDCFB), i.e., solids holdup in everywhere of the riser is larger than 10?%) is easier to be achieved at elevated pressure than in a HDCFB operated at atmospheric pressure. In the current work, the condition of a full HDCFB with Geldart group B particles has been achieved successfully at 0.5?MPa.