The present invention relates to a composite internal in a circulating fluidized bed reactor, comprising guide plates, disturbing plates and 2 to 30 round tubes, wherein the guide plate (3) is secured with its one side to the round tube (1), and the disturbing plate (4) is secured with its one side to the round tube (1) and with its another side to another side of said guide plate (3), with an angle of 50 to 90° included between the guide plate (3) and disturbing plate (4). The round tubes (1) each provided with respective guide plate and disturbing plate are fixed together at one end, and said 2 to 30 round tubes (1) are arranged in one and the same plane. The other end of each round tube (1) is arranged in a radiate manner with respect to the fixed point as a center, and an angle included between each round tube (1) is different from or equal to each other, in a range of 100 to 180°. With said composite internal, replacement of particle groups and exchange between gas phase and solid phase flowing fast in a center area will be effectively improved, thereby improving the effect of gas-solid mass transfer and the work efficiency of the circulating fluidized bed, because the effective disturbance on upward and downward particle groups and the gas flow field are adjusted.