Abstract: In order to improve the separation effect of air-dense medium fluidized bed separator, a new-style air-dense medium fluidized bed separator was develop ed which used anti-dip vibration instead of scraper to discharge gangue, semi-industrial test system was set up and the influence of air volume, feed size, unit handling capacity and feed washability on the separation effect was studied. The results showed that coal with the particle size of 80 ~ 6 mm could be effectively separated by se parator, and the separation efficiency became better with the increase of particle size. The largest unit handling capacity of separator was 7 t/ (h.m2) . Under suitable ai r volume and vibration parameters, easy-to-wash coal could be separated with probable error Epof 0. 05 g/cm3, and difficult-to-wash coal could be separated with proba ble error Epof 0.07 g/cm3, which indicated that a high-precision separation for coal with different washability was achieved.