Coating layer

The invention relates to a coating layer. The coating layer comprises a priming layer, a function layer and a surface covering layer, wherein a transition layer containing special components is arranged between the priming layer and the function layer; the priming layer, the component transition layer, the function layer and the surface covering layer sequentially coat to a substrate, so as to obtain a coating layer tool, wherein the component transition layer is a component gradient layer, and the component gradient layer contains four elements, i.e., Ti, Al, Si and N; the content of Al is gradually reduced along with the increasing of distance away from the surface of the substrate, and the content of Si is gradually increased along with the increasing of distance away from the surface of the substrate. 种涂层，包括打底层、功能层、表面覆盖层，所述打底层与功能层之间施加特定的成分过渡层，所述打底层、成分过渡层、功能层、表面覆盖层依次涂覆于基材上，得到涂层工具，所述成分过渡层为成分梯度层，所述成分梯度层同时包含Ti、Al、Si、N四种元素，其中Al含量随着距基材表面的距离增大而逐渐减小，Si含量随着距基材表面的距离增大而逐渐增大。