The invention relates to a low-head shaft-extension tubular pump turbine and blades thereof, and belongs to the technical field of energy power. The low-head shaft-extension tubular pump turbine comprises a pump turbine body, a reversible motor, a flow channel and a flow guide mechanism, the flow channel comprises a water inlet section flow channel, a guide blade section flow channel, a runner chamber and an S-shaped exhaust water pipe flow channel which are sequentially communicated, a runner is in transmission connection with the reversible motor through a spindle, the flow guide mechanism is arranged on the other side of the runner, the runner comprises a runner boss and a runner cone, the blades are circumferentially and uniformly arranged on the runner boss, the middle of each blade is thick while two sides of each blade are thin, each blade is in the shape of a three-dimensional warped surface, and spatial characteristics of each blade are indicated by an upper section, a middle section and a lower section. The operation conditions of power generation by a turbine and water pumping by a pump can be simultaneously met and are opposite in water flow direction, namely, the same runner needs to simultaneously meet the double requirements of water pumping and power generation, the efficiency of the two operation conditions can be simultaneously considered, and the low-head shaft-extension tubular pump turbine is applicable to a low-head pumped storage power station.