The invention relates to a nanometer / columnar-like crystal mixing structure thermal barrier coating and a preparation method thereof. The mixing structure thermal barrier coating is a nanometer / columnar-like crystal mixing structure coating, and comprises a substrate, a metal bonding layer and a ceramic layer, wherein the metal bonding layer and the ceramic layer are sequentially coated on the substrate, the ceramic layer comprises unmelted nanoparticles, nanometer pores, nanometer crystal and ultrafine crystal, and has cracks perpendicular to the substrate, and the cracks form the columnar-like crystal structure. The mixing structure thermal barrier coating preparation method comprises powder selection, a pretreatment step, a substrate pretreatment step, a metal bonding layer preparation step, and a 6-8% YSZ ceramic layer preparation step. The coating disclosed by the present invention has characteristics of high strain tolerance, excellent thermal insulation performance, high bonding strength, high thermal cycle life, and high thermal shock life, such that the thermal barrier coating has a good comprehensive performance.