An optical communication switch, an optical controlling method, an array substrate and a display device are provided, the optical communication switch including: a first substrate and a second substrate opposite thereto; a first optical medium layer formed therebetween by a phase-change material, which has a first refractive index in a first state in which light rays implement one of an optical path state and an optical drop state, and a second refractive index in a second state in which light rays implement the other one of the optical path state and the optical drop state; a second optical medium layer also formed therebetween and in contact with the first optical medium layer by abutting against it closely, the second optical medium layer having a refractive index matching the first or second refractive index; and a heating device enabling the phase-change material to switch between the first and second states.