The p-on-n HgCdTe infrared detector with As ion implantation is an important technology development route for high operating temperature devices, owing to long minority carrier life, low dark current, high R₀A, etc. Focus on 640×512, 15 μm pitch mid-wavelength infrared HgCdTe focal plane arrays (FPA) devices prepared by As ion implantation and doping, and analysis the performance and dark current under different temperature. The results indicate that the FPA device shows high uniform responsivity and 99.98% operability under 80 K. The number of bad pixels increase with increasing of operating temperature, and the operability decreases to 99.92% and 99.32% under 150 K and 180 K, respectively. Owing to suppression of diffusion current, the dark currents of this device operating within 160-200 K are better than the Rule-07. In addition, for a 300 K background temperature, when working at 150-180 K, tthe device shows high signal-to-noise ratio, which shows the feasibility of high operating temperature detectors.