The utility model discloses a self-pressure-balanced all-welded ball valve which comprises a valve body, a valve deck, a ball, an upper valve rod and a lower valve rod. The ball is mounted in an inner cavity of the valve body. A fluid channel is arranged in the valve body. The ball is provided with a through hole. Sealing devices are arranged between the two ends of the through hole of the ball and the inner wall face of the fluid channel respectively. Each sealing device comprises a valve seat and a sealing element which is fixedly mounted on the valve seat. The position, close to the ball, of the inner wall face of the inner cavity of the valve body is provided with a bulge loop. The end, close to the ball, of the bulge loop is provided with a valve seat mounting groove. The end, deviating from the sealing element, of each valve seat is provided with a spring groove. A regulating groove is formed in the inner side of each spring groove. A sliding block penetrates through each regulating groove and is sleeved with a reset spring. A regulating through hole is formed between the inner end of each regulating groove and the fluid channel. The inner end of each sliding block is provided with at least one first annular sealing groove, and a first sealing ring is connected into the first annular sealing groove in a sleeved mode. By means of the technical scheme, the self-pressure-balanced all-welded ball valve is reasonable in structural design, good in sealing performance, long in service life and low in manufacturing cost.