A rolling shutter driving device includes a motor, a locking assembly and a gearbox. The motor includes a stator and a rotor. The rotor includes a rotary shaft connected to the gearbox. The rotary shaft drives through the gearbox a rolling shutter to extend or retract. The locking assembly includes a brake pad slidingly fitted on the rotary shaft and a rotary member fixedly mounted to the rotary shaft. The brake pad is circumferentially fixed relative to the stator. The brake pad is slidable relative to the rotary shaft so as to be selectively engaged with the rotary member to lock the rotary shaft and hence hold the load in position, or disengaged from the rotary member to unlock the rotary shaft.