Abstract: Using pulse laser deposition（PLD） technology, a series of lead-free（Na_1-xK_x）_0.5Bi_0.5TiO₃ ferroelectric films were fabricated on LaAlO₃（LAO）, （La, Sr）（Al, Ta）O₃（LAST） and SrTiO₃（STO） monocrystalline substrates, respectively.The structure of thin films was analyzed by X-ray diffraction（XRD）.The results show that the thin films growing on flat monocrystalline substrates are all epitaxial.The full wave at half maximum（FWHM） of rocking curve indicates that the crystallinity of thin films growing on（La, Sr）（Al, Ta）O₃ monocrystalline substrates is the best.In addition, laser induced thermoelectric voltage（LITV） signals were observed for the first time in（Na_1-xK_x）_0.5Bi_0.5TiO₃ ferroelectric films growing on 20° vicinal-cut（La, Sr）（Al, Ta）O₃ monocrystalline substrates.The maximum LITV of（Na_1-xK_x）_0.5Bi_0.5TiO₃ ferroelectric films is 31mV under UV light irradiation of 0.48mJ/pulse, which fully satisfies the requirement for pulse laser energy detector.Integrated new-style pulse laser energy detector will probably be exploited.