Parabola drawing tool

Provided is a parabola drawing tool. A first sliding block on a first channel is connected with a second channel perpendicular to the first channel, a drawing pen is arranged on the upper portion of the second sliding block on the second channel, a pen holder shaft is fixed to the axis of the inside of a cylinder of the drawing pen, a torsion spring is arranged on the pen holder shaft in a sleeved mode, the torsion spring is sleeved with a roller, one end of the torsion spring is connected with the pen holder shaft, the other end of the torsion spring is connected with the roller, two strands of multiple winding ropes are wound on the roller and extend out from a rope outlet hole in the cylindrical wall of a pen holder, the outer end of one strand of the ropes is connected with the first sliding block, the outer end of the other strand of the ropes is connected with a point fixing nail, the circumferential portion of the lower end of the pen holder cylinder is provided with a pen clamping cylinder, the axis of the pen clamping cylinder and the axis of the pen holder cylinder are parallel, and the axis of the pen clamping cylinder penetrates through the rope outlet hole. When the parabola drawing tool is used, a person holds the drawing pen with a hand to enable the first sliding block to slide along the first channel and the second sliding block to slide along the second channel, the two strands of the multiple winding ropes are pulled out by overcoming elasticity of the torsion spring, the lengths of the two strands of the multiple winding ropes are the same, and a parabola can be drawn on a drawing board or a blackboard during sliding.