The on-line accurate measurement of high temperature liquid metal flow is of great significance for the safe operation of equipment, industrial process control, optimization of measurement, calibration equipment, etc. According to whether there are obstacles in the measuring instrument structure, this article classifies and analyzes the existing technologies. The advantages and application limitations of the existing measurement technologies are discussed from the principle of measurement technology, application environment, and characteristics. To ensure the accuracy and reliability of the measurement, the online calibration of instruments and meters for high-temperature liquid metal flow measurement is one of the key technologies. This article analyzes the existing technologies. At present, there are few high-temperature liquid metal flow measuring instruments that can work continuously for a long time in the environment above 600℃ , and the online calibration error is 6% ( or more). On the basis of summarizing the existing measurement technologies, the future development direction of the online measurement and the calibration technology of high-temperature liquid metal is prospected. It aims to provide a certain reference for the detection of flow parameters in the nuclear industry and other special industrial production and control process.