A fixing structure of a surveillance device includes a monitor and a secure board. The monitor has a plurality of clips and an alignment gap on a bottom surface of the monitor. The clips are engaged to a plurality of engagement openings of the secure board. The secure board has an alignment flake configured to be inserted into the alignment gap. The alignment gap is engaged with a block element to limit the movement of the alignment flake and to maintain a strong and inflexible connection between the monitor and the secure board.