Heat dissipation device of host

The invention relates to a heat dissipation device of a host, comprising a case top plate, wherein a motor is installed at the center of the case top plate, the shafts of the motor are respectively connected through bearings, and the key connection mode is correspondingly connected with a large gear and a central belt pulley. A ring groove is formed on the top plate of the case, a bearing seat isslidably installed in the ring groove, a rotating shaft is installed on the bearing seat, and a sub-gear, a sub-pulley and a fan blade are installed on the rotating shaft in a top-down order; the beltdividing pulley meshes with the large gear wheel; a belt connecting the belt dividing pulley and the central pulley is arranged between the belt dividing pulley and the central pulley. The device isconvenient to use, and the control fan blade can move along the peripheral position of the top plate of the case while rotating the blowing air, that is, the electronic components installed on the four side walls of the case ar