The present disclosure relates to a MEMS micromirror and a preparation method therefor, in particular to a MEMS micromirror for alleviating optical path blockage, and a preparation method therefor. According to the present disclosure, on the premise of not changing the conditions of a processing technology of a driver and a reflecting mirror in the MEMS micromirror and not affecting the normal operation of the MEMS micromirror, the fixed frame is optimized from the cutting design of a MEMS micromirror wafer, the fixed frame is transformed from a traditional closed frame to a non-closed fixed frame with a notch, while ensuring reliable support, in the large- angle scanning process, emitted light blocked by the traditional fixed frame can be directly emitted from the notch, thereby completely solving the problem of blocking light beams by the fixed frame itself of the MEMS micromirror in the scanning process.