PMNT single crystal is a novel pyroelectric material with superior pyroelectric performance.The fabrication of pyroelectirc infrared detectors based on PMNT single crystal,including lapping and polishing of the crystal,metallization and assembly,is carried out.The pyroelectric coefficient of PMNT chip with thickness of 30 μm is measured and the results indicate that the pyroelectric coefficients of some chips are 9.0×10-4 C/m2K,similar to that of the PMNT single crystal with thickness of 500 μm.Weak pyroelectric current is extracted by a low-noise circuit,and the performance of the fabricated detector is tested and analyzed.