A portable device for controlling an external electrical adjustable apparatus is provided. The portable device comprises a case, a signal transmitter connected to the electrical adjustable apparatus, a tilt sensor sensing a tilted angle, a memory storing a threshold angle and a processor. The processor determines that the electrical adjustable apparatus has collision when receiving a controlling signal used to control the electrical adjustable apparatus and the tilted angle is not less than the threshold angle, and sends a stopping signal to the electrical adjustable apparatus via the signal transmitter for making the electrical adjustable apparatus stop raising/lowering when determining that the electrical adjustable apparatus has collision. This present disclosed example can effectively prevent article placing on the carrying structure from falling and prevent the electrical adjustable apparatus or the obstacle from being damaged by continual stretching/shortening after collision.