The invention is applicable to the field of photoelectric devices A spatial light modulator is disclosed Comprises a base body component, a turnover cover component and a locking component The turnover cover component can turn 0-180 degrees relative to the base component, the locking component is located between the flip cover component and the base component And used to lock the flip cover assembly when the flip cover assembly is flipped to a certain angle The flip cover assembly includes a flip cover main body and a liquid crystal light valve installed on the flip cover main body. The locking assembly includes a flip frame installed on the base assembly and a wave bead screw located between the flip frame and the flip cover main body. The flip cover main body is hinged to the flip frame The spatial light modulator can flip the flip cover assembly within the range of 0 to 180 °, thereby adjusting the optical device; and the spatial light modulator locks the flip cover assembly when it flips to a certain angle by setting a locking assembly between the flip cover assembly and the base assembly, that is, the flip cover assembly can be rotated to 0 °, 90 °, and 180 ° without relying on external force. Stable stop