The Zr/Re co-modified PtAl coating was fabricated by the method of “electroplating Pt vacuum diffusion annealing, composite electroplating Ni-Zr/Re layer+arc ion plating Al layer vacuum diffusion annealing”and the isothermal oxidation experiment was carried out at 1100 ℃ for 200 h. The phase composition and microstructure of the as-annealed coating and the oxidized coating were characterized by scanning electron microscopy, X-ray diffraction and electron microprobe analysis, and the distribution law of the modified elements and the evolution law of the coating microstructure during oxidation were investigated. The results show that the Re-rich precipitates dispersed in the coating aggregate and grow during oxidation and form volatile oxide Re2O7. The Zr solid-solved in the coating co-precipitates with the Ta element diffused into the coating from the substrate alloy, and some Zr entered the Al2O3 scale to form Zr-riched oxides, reducing the growth rate of the Al2O3 scale. In addition, with the mutual diffusion of elements between the coating and the substrate, the β phase in the coating undergoes martensitic transformation. The precipitates in the mutual diffusion zone change from plate-like to particle-like, and the coexistence relationship of Cr-rich precipitates and Re, Cr and W-rich precipitates is found in the secondary reaction zone of the coating.