The utility model provides a singly connected V-shaped porcelain insulator string for +/-500 kV double-circuit lines on a same tower, and relates to an insulator suspension string for a large-capacity transmission line. Ball and bowl hardware fittings of the singly connected V-shaped porcelain insulator string for the +/-500 kV double-circuit lines on the same tower have rotation flexibility in the direction along the lines or perpendicular to the lines. The singly connected V-shaped porcelain insulator string for the +/-500 kV double-circuit lines on the same tower comprises two suspension insulator strings arranged in a V-shaped manner. One end of each suspension insulator string is sequentially connected with a ball head hanging loop, a U-shaped hanging loop, a DB type adjusting plate, U-shaped hanging loops and an EB hanging point hardware fitting. The other ends of the suspension insulator strings are connected with a same suspension link plate through bowl head hanging loops and UL-shaped hanging loops. Equalizer rings are installed on both of the bowl head hanging loops. Suspension wire clamps are installed on the suspension link plate. The singly connected V-shaped porcelain insulator string for the +/-500 kV double-circuit lines on the same tower is safe and reliable under a variety of working conditions, the ball and bowl hardware fittings have good connection flexibility and are flexible to rotate, and that a ball head falls off from a bowl head is avoided.