An electric bed frame includes a fixed rack, a movable rack rotatably connected with the fixed rack, an actuator rotatably connected with the fixed and movable racks and including a cylinder and a push lever movable into and out of the cylinder, and a supporting board disposed on the movable rack and having a hollow portion accommodating a part of the actuator. When the push lever is moved out of the cylinder to make the actuator lengthened, the movable rack is swung upwardly relative to the fixed rack. When the push lever is moved into the cylinder to make the actuator shortened, the movable rack is swung downwardly relative to the fixed rack. As a result, the electric bed frame is thin and can be placed on the traditional bed without heightening the mattress too much, so that the user can get on and off bed conveniently.
