The invention discloses a mobile code spraying machine, and belongs to the technical field of code spraying machines. The problems of higher cost and larger occupied space due to use of two code spraying machines in a traditional small-caliber pipe extruder are mainly solved. The mobile code spraying machine is mainly characterized by comprising a code spraying machine, a fixed rod, a movable rod, a cylinder, a nozzle fixing moving clamp and a limiting mechanism, wherein the fixed rod is a vertical rod; one end of the movable rod is fixed on the cylinder; the limiting mechanism is arranged at the other end of the movable rod; the cylinder is transversely fixed on a cylinder mounting movable clamp; the cylinder mounting movable clamp is mounted on the fixed rod; the nozzle fixing moving clamp is mounted on the movable rod; and a nozzle is fixed on the nozzle fixing moving clamp, and is connected with the code spraying machine through a throat pipe. The mobile code spraying machine has the characteristics of capability of replacing two code spraying machines by one code spraying machine, saving of the equipment investment and reduction of the equipment occupied space, and is mainly applied to a small-caliber pipe extruder.