Abstract: A safety device for toggle clamps is disclosed. The safety device of the present invention comprises a seat portion, a fixing portion, a position-limiting portion, a pull portion and a retaining piece. The fixing portion and the pull portion are connected with the seat portion. The position-limiting portion connects the fixing portion with the pull portion. A positioning hole is provided by either connective juncture of the position-limiting portion, and another positioning hole is provided by either protrusion. To affix the pull portion, we can insert the two insertion ends of the retaining piece into the two positioning holes of the pull portion and the two positioning holes of the position-limiting portion. In addition, a positioning piece may affix an object so that a user may work on the object.