The numerical simulation study was conducted by using Eularian-Eularian two-fluid model on a continuous feeding/unloading bubbling fluidized bed (BFB), which belongs to the TBCFB,and the pressure balance model of feed system was built on the BFB. The bubbling fluidized bed gas-solid hydrodynamics properties were discussed by changing feed pipe length, feed pipe diameter and solid mass flux. The results show that preferable gas-solid contact effect appears when the feed pipe length is larger than 1.1 m and the feed pipe diameter is larger than 0.1 m. Meanwhile, with increasing solid mass flux, solid holdup near the feed port increases as well as the solid holdup and the height of BFB. However, the rise of solid mass flux increases the solid stack height in feed pipes, which can be decreased by increasing the feed pipe diameter, reducing the friction coefficient of pipe wall and the feed pipe embedment depth. This research provides a theoretical basis for the improvement of solid mass flux.