The invention discloses a positioning technological vehicle for assembling a passenger car. The positioning technological vehicle comprises a frame platform and wheels, wherein two sides of a surface of the frame platform are respectively and fixedly provided with a side enclosure; a cantilever support beam is fixed on a surface of the side enclosure; a positioning ejector pin and an auxiliary positioning plate are fixed on the cantilever support beam; and a cantilever support seat is also fixed on a surface of the side enclosure. The positioning technological vehicle is a technological vehicle for transporting sheet metal parts of a passenger car body; track wheels are used for being matched with a track, so that the frame platform can move forward along the track; the positioning ejector pin and the auxiliary positioning plate are adopted to position the position of the sheet metal parts, so that the stability of the sheet metal parts in the transportation process is improved, and the mistake in the installation process is avoided by positioning the installation position of the sheet metal parts; and supporting points on four corners formed by the cantilever support beam and the cantilever support seat play a role in stabilizing the transportation of the sheet metal parts, so that the multipoint use in the technological assembling process is facilitated.