Pipeline welding auxiliary tool in underground pipe gallery

The utility model provides an underground pipe gallery inner pipeline welding auxiliary tool which comprises a cross beam, a telescopic rod arranged in the middle of the cross beam and a pair of limiting rods correspondingly arranged at the two ends of the cross beam, the telescopic rod and the limiting rods are vertically arranged on the cross beam, and a limiting gap capable of being matched with a pipeline exists between the two limiting rods. Mounting seats used for mounting the limiting rods are correspondingly arranged at the two ends of the cross beam, the mounting seats are slidably mounted on the cross beam, the sliding direction of the mounting seats is the same as the length direction of the cross beam, and positioning assemblies used for positioning the mounting seats are arranged at the positions, corresponding to the mounting seats, of the cross beam; one end of the limiting rod is detachably installed on the installation base, the other end of the limiting rod is provided with a limiting block,