A roller shade actuation device includes two actuators arranged in a winding drum, a shaft inserted into the winding drum, and a transmission mechanism. Each actuator includes a housing fixed to the winding drum, a rotary power member arranged in the housing, a driving gear fixed to an output shaft of the rotary power member and coaxial with the output shaft, and a first transmission gear rotatably mounted to the housing and meshed with the driving gear. The actuators are connected linearly in sequence. The driving gear of one actuator adjacent to the transmission mechanism is transmission-matched with and connected to the transmission mechanism, and the driving gears of the remaining actuators are meshed with the first transmission gears of neighboring actuators adjacent to the transmission mechanism. The actuators are connected in series to form an actuator combination through the driving gears and the first transmission gears.