The present disclosure provides an azulene ring-containing compound, its use, and an organic photoelectric device including the same. The azulene ring-containing compound is a compound comprising a structure of Formula I. The organic photoelectric device includes an anode, a cathode, and one or more organic thin film layers located between the anode and the cathode; and at least one of the organic thin film layers contains the above-mentioned azulene ring-containing compound comprising the structure of Formula I. The azulene ring-containing compound provided by the present disclosure has an energy level difference ΔEst≤0.3 eV between the lowest singlet state S1 and the lowest triplet state T1, and has a light-emitting mechanism of a thermally activated delayed fluorescent material, and can be used as a thermally activated delayed fluorescent material for organic photoelectric device, so that the light-emitting efficiency of the device is improved.