A heat dissipation module, comprising: a first fan having a first hub and a plurality of first fan blades disposed on the first hub; a second fan having a second hub and a plurality of second fan blades disposed on the second hub; and a motor connected to the first hub and adapted to drive the first hub and the second hub to rotate; wherein the first hub and the second hub are movably connected to each other in an axial direction; characterized in that the motor is configured to rotate the first fan and the second fan in a first rotation direction or in a second rotation direction opposite to the first rotation direction, wherein the second hub comprises a sliding groove extending in parallel with the axial direction an engaging groove communicating with the sliding groove and extending perpendicular to the axial direction, and the first hub comprises a latch for releasably engaging with the engaging groove of the second hub, wherein when the motor drives the first fan and the second fan in the first rotation direction, the latch of the first hub is engaged with the engaging groove of the second hub so that the first hub coincides with the second hub in the axial direction and the plurality of first fan blades coincide in the axial direction with the plurality of second fan blades, and when the motor drives the first fan and the second fan in the second rotation direction, the latch of the first hub is released from engagement with the engaging groove of the second hub so that the first hub and the second hub can be separated from each other in the axial direction and the plurality of first fan blades and the plurality of second fan blades are separated from each other to be alternatively arranged. a first fan having a first hub and a plurality of first fan blades disposed on the first hub; a second fan having a second hub and a plurality of second fan blades disposed on the second hub; and a motor connected to the first hub and adapted to drive the first hub and the second hub to rotate; wherein the first hub and the second hub are movably connected to each other in an axial direction; characterized in that the motor is configured to rotate the first fan and the second fan in a first rotation direction or in a second rotation direction opposite to the first rotation direction, wherein the second hub comprises a sliding groove extending in parallel with the axial direction an engaging groove communicating with the sliding groove and extending perpendicular to the axial direction, and the first hub comprises a latch for releasably engaging with the engaging groove of the second hub, wherein when the motor drives the first fan and the second fan in the first rotation direction, the latch of the first hub is engaged with the engaging groove of the second hub so that the first hub coincides with the second hub in the axial direction and the plurality of first fan blades coincide in the axial direction with the plurality of second fan blades, and when the motor drives the first fan and the second fan in the second rotation direction, the latch of the first hub is released from engagement with the engaging groove of the second hub so that the first hub and the second hub can be separated from each other in the axial direction and the plurality of first fan blades and the plurality of second fan blades are separated from each other to be alternatively arranged.