The invention relates to the technical field of smart home, and discloses an auxiliary device and method capable of randomly adjusting the height of a cat eye and higher in safety. The auxiliary device comprises an anti-theft door, wherein the interior of the anti-theft door is movably connected with an eye hole. A rotary knob rotates to enable a clamping block to be close to or far away from theinner wall of a rotary disc, so that the movement condition of the rotary disc is controlled, a power source is provided for follow-up operation of adjusting the position of the eye hole, linkage between structures is improved, operation is more convenient and faster, stopping is conducted in time after adjustment is completed, a connecting rod pulls a reversing rod to swing left and right to makea second gear rotate intermittently, accordingly the eye hole moves upwards or downwards, the position of the eye hole is adjusted, the device is convenient for people of different heights to use, high practicability is achieved, the position of a protruding block of a baffle in an arc groove of the anti-theft door is changed, the rotating direction of the second gear is changed, the moving direction of the eye hole is changed, therefore the position of the eye hole can be changed at will, the device has high flexibility, and the operation is more convenient and faster.