Micro-scanning technique and its benefits in infrared focal plane array (FPA) imaging are discussed. Different micro-scanning schemes and their property are described in detail. The advantages and drawbacks of each scheme are compared. The possible schemes for engineering application are presented. The research direction in micro-scanning infrared focal plane array imaging is pointed out. As an example, we design a micro-scanning optical system suitable for long wave infrared optical system whose operating wavelength range is 8～14 μm, F number is 1, and focal length is 150 mm. It was an uncooled 384 pixel×288 pixel VOx focal plane array detector. Moreover, its image quality is evaluated with the Code Ⅴ optical design software. And the infrared mico-scanning system configuration is also introduced.