A series fan comprising: a first fan including a first frame body, a first dynamic blade impeller and a first shaft seat, two sides of the first frame body being respectively formed with a wind incoming side and a connection side, the first shaft seat being disposed at a center of the wind incoming side, a first static blade being disposed between the first shaft seat and inner circumference of the first frame body, the first dynamic blade impeller being pivotally disposed on the first shaft seat, the first dynamic blade impeller having multiple first dynamic blades, a second fan including a second frame body, a second dynamic blade impeller and a second shaft seat, two sides of the second frame body being respectively formed with a wind outgoing side and a mating side, the mating side being mated with the connection side in communication therewith, the second shaft seat being disposed at a center of the wind outgoing side, a second static blade being disposed between the second shaft seat and inner circumference of the second frame body, the second dynamic blade impeller being pivotally disposed on the second shaft seat, the second dynamic blade impeller having multiple second dynamic blades, characterized in that each first dynamic blade having at least one connection section; and each second dynamic blade having at least one connected section, the connected section of the second dynamic blade being connected with the connection section of the first dynamic blade to form integrally a driving blade, the first fan being upside-down placed on the second fan and thus serially reverse-connected with the second fan. a first fan including a first frame body, a first dynamic blade impeller and a first shaft seat, two sides of the first frame body being respectively formed with a wind incoming side and a connection side, the first shaft seat being disposed at a center of the wind incoming side, a first static blade being disposed between the first shaft seat and inner circumference of the first frame body, the first dynamic blade impeller being pivotally disposed on the first shaft seat, the first dynamic blade impeller having multiple first dynamic blades, a second fan including a second frame body, a second dynamic blade impeller and a second shaft seat, two sides of the second frame body being respectively formed with a wind outgoing side and a mating side, the mating side being mated with the connection side in communication therewith, the second shaft seat being disposed at a center of the wind outgoing side, a second static blade being disposed between the second shaft seat and inner circumference of the second frame body, the second dynamic blade impeller being pivotally disposed on the second shaft seat, the second dynamic blade impeller having multiple second dynamic blades, characterized in that each first dynamic blade having at least one connection section; and each second dynamic blade having at least one connected section, the connected section of the second dynamic blade being connected with the connection section of the first dynamic blade to form integrally a driving blade, the first fan being upside-down placed on the second fan and thus serially reverse-connected with the second fan.