The utility model relates to the technical field of temperature monitoring of pipeline welding. The device is a pipeline welding temperature monitoring device. The system comprises a control circuit,a terminal node, a temperature measuring device used for measuring the temperature of a pipeline and a power switch used for controlling on-off of a heating heat preservation blanket wrapping a pipeline welding opening. the control circuit comprises a micro-control unit, a driving circuit, a display, an analog-to-digital conversion unit, an interface unit and a power supply management unit; the temperature measuring device converts a measured temperature value into a digital signal through the analog-to-digital conversion unit and sends the digital signal to the micro-control unit, and the micro-control unit is used for judging whether the measured temperature is within the range required by the preheating temperature process of pipeline welding or not. The infrared temperature measuring device is reasonable and compact in structure and convenient to use, the infrared temperature measuring sensor measures and uploads the actual temperature of the preheating pipeline to the micro-control unit, the micro-control unit judges whether the measured temperature is within the technological requirement range of the preheating temperature for pipeline welding or not, and the welding qualityof the pipeline is improved.