Combustion supporting device of internal combustion engine

A combustion supporting device is applicable to being connected with a negative pressure pipe of an internal combustion engine and used for holding working liquid. The combustion supporting device of the internal combustion engine comprises a vaporization bottle and an overflow resisting bottle, wherein the vaporization bottle holds the working liquid and is communicated with the outside, and the overflow resisting bottle is connected with the negative pressure tube and communicated with the vaporization bottle. When the internal combustion engine works, the working liquid is enabled to generate bubbles and vaporized to become water vapor, and the water vapor enters the internal combustion engine to mixedly explode with fuel, so that increasing of fuel atomization, full combustion of fuel, strengthening of torsion of a piston, clearing of carbon deposition, reduction of harmful exhaust gas emission and the like are achieved.