The present invention relates to a converter roughing slag detection method based on infrared temperature measurement. The method comprises: (1) employing an infrared thermal imager as an image and temperature data collection device, wherein the information output end of the infrared thermal imager is connected with an industrial control computer, the instruction output end of the industrial control computer is connected with the information input port of a converter PLC electric control cabinet; (2) disposing the infrared thermal imager at the position far away from the convertor and connecting the infrared thermal imager with the industrial control computer, performing real-time shooting of the steel tapping and steel stream images in the steel tapping process, obtaining the image data, and obtaining the real-time temperature data of the molten steel; (3) transmitting the obtained image data and real-time temperature data collected by the infrared thermal imager to the industrial control computer, and emitting an instruction through the industrial control computer to the converter PLC electric control cabinet through calculation and analysis; and (4) closing a sliding plate through a converter PLC electric control cabinet hydraulic pressure station, and finishing the slag stopping. The converter roughing slag detection method based on infrared temperature measurement can directly provide the infrared radiation temperature of each point of the surface of the detection molten steel through adoption of the infrared temperature measurement detection method, namely one single quantity is detected, the temperature measurement range is 300-2000 degrees, and the infrared radiation temperature of the molten steel in the steel tapping process can be directly obtained.