The invention provides a high-
emissivity and high-entropy 
ceramic material and a preparation method and application thereof, and belongs to the technical field of high-entropy 
ceramic materials. Five 
rare earth elements with different 
doping proportions are simultaneously introduced into the 
crystal lattice position of La, the number of 
impurity energy levels between the 
valence band top and the 
conduction band bottom of LaMgAl11O19 is increased, the forbidden 
band width is reduced, electrons in the 
impurity energy levels can absorb energy of 
infrared light to jump to the 
conduction band, and then the spectral 
emissivity of the corresponding 
wave band is improved; according to the invention, Pr, Ce or Eu elements with variable valence are introduced into the LaMgAl11O19 
ceramic material, and when the valence state of the Pr, Ce or Eu elements is changed, the concentration of free electrons in a 
system can be increased (for example, the valence of Pr < 3 + > is changed to Pr < 4 + >) so that the absorption of free carriers to 
infrared light is promoted, and the improvement of spectral 
emissivity is also facilitated. The spectral emissivity of the ceramic material in the 
infrared band of 3-5 [mu] m is greater than 0.85, and the ceramic material has a good application prospect.