Disclosed are a spatial light modulator and a display device. The spatial light modulator includes: a substrate; the phase modulation devices disposed on a side of the substrate and arranged in an array, and each of the plurality of phase modulation devices includes a plurality of electrodes, the plurality of electrodes includes at least one first electrode and at least one second electrode, the at least one first electrode and the at least one second electrode are alternately arranged in a direction departing from the substrate, and a piezoelectric layer is sandwiched between the first electrode and the second electrode; and the piezoelectric layer comprises a piezoelectric material.