The invention discloses a glue dispensing gun capable of mixing glue A and glue B. The glue dispensing gun comprises a gun body, two abreast valve rod cavities are arranged in the gun body, a valve rod is arranged in each valve rod cavity, the middle section of each valve rod is a rod body, the head of each valve rod is a piston, the bottom of each valve rod is an extruding head, the tops of the valve rod cavities in the gun body are connected with cylinders in a communicated mode, an air inlet is arranged on each cylinder at the position facing the outer side of the gun body, air outlets are arranged in the top of the gun body, the bottoms of the valve rod cavities are boosting cavities, glue accommodating cavities communicated with each other are arranged below the boosting cavities, the pistons move vertically in the cylinders, the extruding heads move vertically in the boosting cavities, a glue port A and a glue port B which are opposite are formed in the middle section of the gun body and communicated with corresponding valve rod cavities, glue guiding pipes are arranged at the bottoms of the glue accommodating cavities, and the two glue guiding pipes are collected at a glue outlet nozzle. By separating two kinds of glue and boosting the glue through the valve rods to the glue outlet nozzle to mix and dispense the glue, glue mixing time is greatly shortened, and blocking of a pipeline due to mixing and solidification of the glue is avoided.