The invention discloses a real-time monitoring and safety warning device for the temperature of a furnace tube of a tubular industrial furnace. The real-time monitoring and safety warning device comprises four parts, namely a detecting device, an electrical control device, an air source control cabinet and a computer process and control part. According to the characteristics of infrared radiation of the furnace tube, an infrared radiation image of the furnace tube is obtained by an optical imaging system suitable for colorimetric temperature measurement, the infrared radiation image is analyzed by adopting technologies of digital image processing, pattern recognition, computer vision measurement and the like, the distribution state of the temperature on the surface of the furnace tube is obtained in real time by virtue of the colorimetric temperature measurement technology so as to give an overtemperature alarm, and the change trend of the distribution of a temperature field of the furnace tube is obtained by utilizing a database to analyze history data in the whole operation cycle of the furnace tube so as to provide intuitive and effective basis for the evaluation of the efficiency of a heating furnace and the residual service life of the furnace tube. The real-time monitoring and safety warning device provides key parameters for the optimization of burning of the industrial furnace, and has great significance on ensuring safety production and improving productive efficiency.