A display panel, a method for preparing a display panel and a method for adjusting an intensity of ambient light reflected on a display panel are provided in embodiments of the disclosure. The display panel includes: a base substrate; a plurality of sub-pixel units (20) on the base substrate comprising a plurality of light emitting portions respectively; an electrochromic assembly on a light-emergent side of the plurality of light emitting portions; and a light intensity detector configured to detect an incident intensity of ambient light, and the electrochromic assembly comprises a plurality of electrochromic portions covering the plurality of light emitting portions, respectively; and transmittance of the plurality of electrochromic portions for ambient light varies with a change in the incident intensity of ambient light.