The Trinity Cathedral was built over eight years, from 1776 to 1784, thanks to donations from the residents of Ustyug. This five-domed structure features a separate bell tower, which helped maintain the harmony of its volumes. The bell tower is set on a square base, supported by arches connecting massive quadrangular pillars. The octagonal bell chamber is topped with a low tent roof with two rows of sound windows, where the upper ones are smaller than the lower ones, enhancing the effect of perspective reduction and emphasizing the grandeur of the building.

The cubic-shaped cathedral is surrounded on three sides by a two-story gallery. Its decorations include typical pilasters, a stepped cornice, and zakomaras. The altar chapel stands out against the simple extension of the Archangel Cathedral due to its three-lobed wavy apses that smoothly transition to the main volume of the temple. The upward aspiration of the cathedral is highlighted by the five domes on faceted drums rising from rows of kokoshniks. The windows of the cathedral are framed with green tiles. At the level of the second floor of the gallery, there is a wide belt, with similar motifs used in the decoration of the bell tower's square base.

The Trinity Cathedral is also known for its five-tiered carved iconostasis from the 18th century, which is one of the finest examples of Russian decorative art. The iconostasis was created by the Totma masters, brothers Nikolai and Timofey Bogdanov. In addition to the delicate carvings of the columns and cartouches, it is adorned with bas-relief figures of evangelists and cherubs. The overall impression of the iconostasis's richness is enhanced by the gilding done by the P.A. Labzin artel using a complex technique of double application with cirovkas and shaped prints on wet levkas.

Since 1995, by agreement with the museum administration, a service has been held in the church on the Feast of the Holy Trinity.