The invention relates to the technical field of machine casting, in particular to a method for fixing a deep-drawn pipeline core for casting a large-scale machine body. The method comprises the following steps of: a, welding a fixing nut on the core skeleton of the deep-drawn pipeline core before manufacturing the core; b, embedding a square pressure plate into a V-shaped core in the process of manufacturing the core; c, tightly hanging the deep-drawn pipeline core on the V-shaped core in the process of matching a mould; d, controlling the height of the deep-drawn pipeline core during adjustment; e, fixing the two ends of the core on an end box after the core is loaded, and reserving a gap which is required by expanding the core skeleton by heating; f, cutting off a protruding part on thetop of a stud bolt after the casting is finished; and g, removing the stud bolt by machining in the process of mechanically drilling an oil filling channel. The method can ensure that the deep-drawn pipeline core does not move in the process of pouring the machine body, a rejection rate is reduced and cost is greatly saved.