The invention discloses a blasting method of a through oblique-pulling truss girder bridge. The blasting method comprises the following steps of 1, filling of a river channel with land; 2, cleaning in the range of the river channel; 3, blasting designing, drilling and explosive charging; 4, blasting network and sequence establishing; 5, guard setting and blasting initiation; and 6, cleaning after blasting. The whole bridge is removed at a time through blasting by combining a drilling blasting method with a water pressure blasting method, girders in the river channel all fall into a dug trench after the blasting, the construction cost is low, the construction safety control difficulty is low, the construction difficulty is low, the influence on later construction is small, the dust diffusion distance is effectively shortened, the time of occupying a shipping lane is greatly shortened, and the blasting method is particularly suitable for busy shipping lane sections having high navigation requirements and not allowing long-time navigation suspension.