Nikolai Martyanov, son of the Vilnius forest ranger Mikhail Martyanov, received his education at the assistant pharmacists' courses at the Medical-Surgical Academy in St. Petersburg and Moscow University. He worked in pharmacies in Tsarskoye Selo, Moscow, and St. Petersburg. In 1872, after obtaining the title of pharmacist, Martyanov moved to Kazan, where he was able to pursue his scientific interests thanks to Kazan University. He became a member of the university's naturalists' society, giving lectures and publishing articles on local flora. However, he was drawn to the wilderness, and when Minusinsk doctor A. V. Malinin offered him a job at the city pharmacy, he accepted.

From 1874, Martyanov lived in Minusinsk, where he organized a local history circle and headed the local museum from 1877 to 1904. He conducted scientific expeditions, exploring the south of the Yenisei province, Kuznetsky Alatau, and the Sayan Mountains, collecting ethnographic collections of the Khakas people. Martyanov actively corresponded with well-known scientists such as P. P. Semenov and N. M. Yadrintsev.

In January 1886, George Kennan arrived in Minusinsk, who first visited Martyanov. Kennan recalled that Martyanov was a gracious host, knew about the guests' journey from the newspapers, and was glad they visited Minusinsk. Martyanov modestly expressed concern that the museum might not meet expectations but offered to show it. The Minusinsk museum, created by Martyanov, became a significant achievement despite modest resources. He began collecting items immediately upon arriving in Minusinsk, involving schoolchildren and teachers in the process. Soon, collections began arriving at his pharmacy, and within two years, he gathered about 1,500 items and a library of over 1,000 books.

By 1879, the museum had over 6,000 items, and the library had about 3,100 volumes. Soon, the museum moved to a new building, occupying six or seven rooms. The museum's collections were classified into six departments: natural history, ethnography, archaeology, agriculture, industry, and educational aids.

Kennan handed Martyanov letters from N. M. Yadrintsev and I. T. Savenkov, who recommended the traveler and his companion. Martyanov introduced Kennan to the members of the Museum Committee and organized a trip to the Kachinsk steppe to meet the local population. These activities served as a cover for Kennan's main goal, meeting with political exiles.

On February 4, Kennan said goodbye to Martyanov and his colleagues, who escorted him to the road to Tomsk. In April 1886, a committee was established to build a building for the museum, and in May 1887, its foundation was laid. In 1890, the museum opened in its own building, and Martyanov and other local authorities spoke at the ceremony.

Martyanov was a member of various scientific societies and was awarded the Orders of St. Stanislaus and St. Anna for his services to society. However, the intense work undermined his health, and in 1904 he went to Crimea for treatment, where he passed away on February 13. His funeral became an event for the entire city.