The invention discloses a solar mirror bracket welding fixture comprising two fixture bases arranged symmetrically. The two ends of the two fixture bases are fixedly connected with two horizontal square pipe limiting devices arranged perpendicularly to the fixture bases separately; a horizontal square pipe pressing device is arranged between the horizontal square pipe limiting devices; the two ends of the fixture base are provided with four square pipe vertical locating devices symmetrically, and the square pipe vertical locating devices are located between the two horizontal square pipe limiting devices; and the fixture base is provided with a plurality of sheet metal part vertical locating devices, vertical square pipe pressing devices and vertical square pipe jacking devices in sequence. The solar mirror bracket welding fixture provided by the invention is high in welding quality and safety, and the welding efficiency is improved.