A display substrate and a preparation method therefor, and a display apparatus. The display substrate includes a light-emitting unit layer arranged on a base, and a reflecting layer arranged on the light-emitting unit layer, wherein the light-emitting unit layer comprises a plurality of light-emitting units corresponding to different colors, and the reflecting layer is provided with light transmission holes corresponding to the plurality of light-emitting units on a one-to-one basis; and a light modulation layer is arranged on the side of the reflective layer away from the base, and the light modulation layer is configured to reflect some light rays in a blue light waveband and transmit light rays in wavebands other than the blue light waveband.