The invention relates to a method for controlling blasting by double-medium decoupling fracture and damage and a blasting cartridge thereof. The method adopts cylindrical explosive, detonator or primacord to explode a hole on a blasted rock body. The method is characterized in that water and air are simultaneously used in the hole to separate explosive, wherein, the water medium is aligned to the side of a free surface, while the air medium is aligned to the side of a reserved surface; the uniform distributing state of explosive energy can be changed by using the characteristics that the two media have different efficiencies of transmitting energy, thereby achieving the function of completely destroying one side and protecting the reserved surface during blasting, and forming a flat fracture surface. The blasting cartridge consists of an outer tube, an inner tube and a separating wall, wherein, the separating wall separates a cavity formed between the outer tube and the inner tube into a medium chamber for containing the water medium and a medium chamber for containing the air medium; and an explosive chamber for placing the cylindrical explosive is arranged in the inner tube. The invention has the advantages of easily operating, improving explosive power and agglomerating rate, protecting stability of wall rock, reducing harm of dust and noise, and the like, and can be widely applied to smooth blasting projects such as tunnels, side slopes, water conservancies, mining, and the like.