The extraordinary optical and electronic properties of anisotropic two-dimensional materials,such as black phosphorus,ReS2,and GeSe,enable them a promising component of polarization-sensitive photodetectors.However,these applications are significantly limited by the challenges of air-stability,response time,and linearly dichroic ratio.Interestingly,palladium diselenide (PdSe2) with high air stability is an emerging material that has robust in-plane anisotropy induced by its asymmetric pentagonal lattice structure.We have successfully prepared a few-layer PdSe2 using micromechanical exfoliation,and here we demonstrate the strong linear dichroism behavior of PdSe2 by polarization-resolved absorption spectra measurements.Such unique linear dichroism,endows the PdSe2 photodetector powerful ability to detect polarized light.The photodetector based on 5L PdSe2,as tested with polarization-dependent photocurrent mapping,exhibited competitive capability to detect polarized light,achieving a significant photocurrent on/off ratio (＞ 102),the quite fast response time (＜ 11 ms) and robust linearly dichroic ratios (Imax//Imin ≈≈ 1.9 at 532 nm).These results are essential advance in the development of polarization-sensitive photodetector,a crucial step towards opening up a new avenue for the application of 2D optoelectronic devices.