The invention relates to a special pipe forming technology for a log splitter oil cylinder. The technology comprises the steps that 1, uncoiling is carried out, and particularly a steel belt coil is uncoiled; 2, leveling is carried out, and particularly the uncoiled steel belt is leveled and conveyed to a next station; 3, end flattening and butt welding are carried out, particularly, the head andthe tail of the leveled steel belt are sheared and flattened, and the tail of the sheared and end-flattened steel belt and the head of a next sheared and end-flattened steel belt are welded together;4, prestoring is carried out, and particularly the but-connected steel belts are conveyed into a loop storage bin; 5, forming is carried out, particularly, the steel belts in the loop storage bin areconveyed into a forming machine, and the steel belts are gradually bent in sequence to form pipe blanks to be welded; 6, high-frequency welding is carried out, and particularly high-frequency weldingis carried out after the two butt-connected ends of the pipe blanks are extruded to the certain opening angle; 7, water cooling is carried out, the steel pipes welded at a high frequency are cooled toroom temperature in a spraying mode; 8, special gradient sizing is carried out, and particularly the water-cooled steel pipes are sized through a sizing unit; and 9, contour machining is carried out,and particularly the sized steel pips are cut to specific lengths.