A motor-driving mechanism includes a motor and a lifting lever. The lifting lever is rotatable between a lifted position and a lowered position, and includes first section and a second section. The first section is pivotably connected to the motor. The second section is connected to the first section in such a way that the first section and the second section as a whole are drivable by the motor to rotate in a first direction from the lowered position toward the lifted position, and the first section is drivable by the motor to rotate relative to the second section in a second direction from the lowered position toward a third position while the second section remains at the lowered position, the second direction being opposite to the first direction. A motor-driven bed utilizing the motor-driving mechanism is also disclosed.