The invention discloses a method for manufacturing a motor-vehicle seat headrest installation base, and relates to the field of automobiles. The method includes the steps of punch forming, welding and assembling. The motor-vehicle seat headrest installation base comprises two insertion rod sleeve installation bases installed on a backrest main frame tube. Insertion rod sleeves are installed in the insertion rod sleeve installation bases. Each insertion rod sleeve installation base comprises a groove-shaped base body and a bolt inserted nearby a groove opening of the base body, and a gap is formed between a bolt hole of each insertion rod sleeve installation base and the corresponding bolt in the groove depth direction of the corresponding base body. A gap is also formed between the base body of each insertion rod sleeve installation base and the insertion rod sleeve inserted in a groove of the base body in the groove width direction. The method includes the welding steps that openings, in the two sides of the base bodies, of the groove openings of the two insertion rod sleeve installation bases are arranged on the backrest main frame tube, and welding is carried out at the portions of the top ends of the two sides, in contact with the backrest main frame tube, of the groove openings of the base bodies. By means of the method, the problems that a manufacturing technology for the seat headrest installation base is complex, the headrest installation base is poor in adaptability, and pulling and inserting are not smooth can be solved.