The transparent wind shield is a key structural part of the aircraft, requiring outstanding performance. To reduce weight, the aircraft transparent wind shield adopts a heterogeneous multi-layer composite structure of “organic glasstransparent polycarbonate-organic glass”, where the performance is closely related to the thickness of each layer of the transparent wind shield. Existing measurement methods cannot meet the comprehensive requirements for efficient and high-precision layer-by-layer thickness measurement of the transparent wind shield. Therefore, a new method for spectral-domain low-coherence measurement of the multi-layer transparent wind shield is proposed. Firstly, by using the orthogonal dispersion to enhance dispersion capability, the measurement range is increased. Then, a mapping model between the thickness of the transparent windshield and the spectral wavenumber is formulated, and the model parameters are calibrated with high-precision parallel flat crystal. Finally, a measurement system is established. Experimental results show that the proposed method has a maximum range exceeding 41 mm, with micrometer-level measurement accuracy, and a measurement speed less than 8 ms. It can meet the requirements for thickness measurement of the multilayer aircraft transparent windshield.