Embodiments of the present disclosure provide a MEMS light valve, a pixel array and a display apparatus. The MEMS light valve includes a first grating including first openings arranged in a matrix; a second grating, parallel to the first grating and including light emitting areas corresponding to the first openings, wherein the second grating is capable of moving with respect to the first grating along a shifting direction parallel to the first grating. Light emitting materials which emit lights having certain wavelengths by means of excitation by external lights are provided on the light emitting areas.