A design method of field-widened Michelson interferometer (FWMI) applied as the spectroscopic filter for high spectral resolution lidars (HSRLs) is proposed. The theoretical principles and design criteria are described in detail. Making use of the field-widen and thermal compensation conditions, the FWMI can achieve large incident field within a certain temperature range. The design result of the near-infrared FWMI is provided. The performance analysis of designed FWMI indicates that its available incident divergence is larger than 2°, and its working performance remains constant within (20±0.5) ℃. What′s more, according to the tolerance analysis, the design result meets the current glass processing technic. The design procedure and method introduced have guiding significance for the FWMI design and production.