In this paper， an investigation into the preparation technology and performance of 1280×1024 middle-wavelength （MW） HgCdTe infrared focal plane arrays （IRFPAs） with a pixel size of 10μm was introduced. The manufacturing process of these high-resolution FPAs involved the utilization of B+ injection to establish small-sized n-on-p junctions and the application of high-precision In-bump interconnection. Through development of the process， the adverse effects of the mismatch between HgCdTe devices and readout integrated circuits （ROICs） were mitigated， thereby reducing the likelihood of device failure. The assembled FPAs were evaluated to photoelectric performance evaluation at a temperature of 85 K. The experimental results demonstrate that the detector''s spectral response encompasses a wavelength range of 3.67 μm to 4.88 μm. The highest pixel operability of the assembly can reach 99.95%. The average values of the noise equivalent temperature difference （NETD） and the dark current density for all the pixels of the assembly are respectively less than 16 mK and 2.1×10^-8 A/cm². In comparison with a 15 μm pitch detector， the utilization of the 1280×1024 10 μm MWIR detector facilitated the capture of finer details in target images and extended the identification range. At present， this technology has been successfully transferred to the HgCdTe FPA production line of Zhejiang Juexin Microelectronics Co. Ltd. （ZJM）. The production capacity and yield are constantly increasing.