Abstract: With rapid development of modern optical manufacturing technologies, industrial robot polishing has a wide range of application scenarios and broad development potential in the field of optical manufacturing. The integration of in-situ inspection is a key to improving the reliability and efficiency of precision manufacturing. Deflectometry is a promising in-situ measuring method due to its large dynamic range and structural flexibility. The measurement principles, calibration methods, phase retrieval, surface reconstruction, scope extension etc are presented systematically. The key problems of height-slope ambiguity and position-angle uncertainty are analyzed in details. High-precision measurement of complex optical elements is realized, which is of great significance to the intelligent manufacturing of key optical components.