In order to meet the demand for high?precision automatic detection of multiple wafer defects during the manufacturing process of micro light emitting diode (Micro?LED) chips, a large?field?of?view polarisation dual?channel Micro?LED wafer defects automatic optical inspection system has been designed. The system integrates microscopic imaging technology with polarisation imaging technology, thereby enhancing the contrast of Micro?LED wafer defect images and enhancing the detection accuracy. The system utilises infinite conjugate microscopic objectives and barrel lenses, which expand the image area of wafer samples captured in a single exposure and improve the detection efficiency. Experiments have been conducted to verify the performance of the large?field?of?view dual?channel Micro?LED wafer defect optical inspection system, and the results demonstrate that: the system's magnification is 20, the illumination uniformity is up to 91.6%, and the maximum image field?of?view is 33 mm; The modulation transfer function (MTF) curve of the system is close to the diffraction limit at the Nyquist frequency of 31 lp / mm, which can satisfy the object resolving power of 0.8 μm. The system has been shown to enhance the information entropy, edge intensity, standard deviation and average gradient of polarimetric images in comparison to traditional grey?scale images by 25.6%, 24.9%, 33% and 173.3%, respectively. The large?field?of?view dual?channel Micro?LED wafer defect optical inspection system has been demonstrated to capture the characteristic information of different types of defects in real time, with high recognition efficiency, low missed detection rate and other advantages, providing a strong support for the high?precision inspection of Micro?LED wafer production quality.