It has a fine white eyebrow above a black eyestripe, which is distinct when the plumage is fresh, and exhibits a small degree of sexual dimorphism.

In 1953, the Dutch ornithologists Karel Voous and John G. van Marle thought that the Yunnan nuthatch formed a link between the canadensis and europaea groups, and simultaneously that it was very closely related to the canadensis group, of which it was a basal representative in terms of distribution and plumage.

[8] In 2014, Éric Pasquet and colleagues published a nuclear and mitochondrial DNA-based phylogeny of 21 species of nuthatch and confirmed the 1998 study relationships within the canadensis group, adding the Yunnan nuthatch, which is found to be the most basal species of the group.

The upperparts of the Yunnan nuthatch are blue-grey, including the calotte, despite being separated from the upper mantle by a paler area.

It has a thin white eyebrow, which extends to the forehead and surmounts a black eyestripe, which widens noticeably on the back, on the sides of the mantle.

[6] Its irises are dark brown, the bill gray-black with the base of the lower mandible horny or yellowish, and the legs and feet are gray-brown.

[6] The species exhibits little sexual dimorphism, but the black of the female's eyestripe is on average less intense and its underparts are duller and grayer.

[6] The young is duller than the adult, with the eyebrow less marked and not extending to the forehead, sometimes almost absent and consisting of a lighter cap margin.

The throat is whiter, but the rest of the underparts are duller, grayish cinnamon, though not as pale as in a worn plumaged adult.

The Yunnan nuthatch is a fairly noisy bird, and typically makes many individual sounds: nit, kni, tit, pit, or a low and nasal toik.

[6] In 1987, Chinese ornithologist Zheng Zuoxin described the Yunnan nuthatch as rare,[12] but it is locally common in areas such as Lijiang's pine forests.

It has a small range of around 170,000 square kilometres (66,000 sq mi),[13] and the bird disappeared from several locations in the early twentieth century.