The spontaneous emission characteristics of the two-level atom near the surface of Chern insulator and chiral metamaterial medium is investigated. The matrices of the reflection coefficients of the chiral medium surface and the interface of chiral medium and Chern insulator are calculated, and the expression of the spontaneous decay rate of the two-level atom in this environment is obtained according to the dyadic Green's function. The atomic spontaneous emission under the influence of the characteristic parameters of the chiral medium and Chern insulator is numerically analyzed. The spontaneous decay rate of the dipoles parallel and perpendicular to the interface is discussed respectively, and the spontaneous emission in the radiation mode and the evanescent mode is analyzed respectively. The results show that the spontaneous decay rate of atoms near the interface of the chiral medium is enhanced compared with the common dielectrics due to the presence of chiral parameters. Under the influence of Chern insulator, the spontaneous emission of atoms near the interface is conspicuously inhibited, and for the larger chiral parameter, the suppression effect of the Chern insulator is more significant.