The development of double-color detector at home and abroad is introduced. And the performance of the Si-based 320×256 SW/MW double-color infrared detector developed by the unit is reported. Under the test condition of 77 K, the blind element rates of the short wave(SW)and medium wave (MW)bands are 0.88% and 1.47% respectively. The average peak detection rate are 2.21×1012 cm·Hz1/2·W -1and 2.13×1011 cm·Hz1/2·W -1 respectively. The back cutoff wavelengths are 3.129 m and 5.285 m respectively. The spectral crosstalk from SW to MW band is 1.38%, the crosstalk from MW to SW band is 2.82%. At the same time, the detector has good imaging results in the dual-band, which provides a foundation for further research on multi-band detectors with larger array and better performance.