Pozdneev was born in Leningrad. His father taught mathematics at the Leningrad Institute of Railroad Transport Engineers.
In 1946 Pozdneev entered the famous Secondary Art School at the Institute of Painting, Sculpture and Architecture named after Ilya Repin where he studied with Vladimir Gorb and Mikhail Bernshtein. In 1950, after graduating from the Secondary Art School Pozdneev was adopted for the first course of the painting department of Repin Institute of Arts. His teachers were Alexander Debler, Elena Tabakova, Andrei Mylnikov, Vladislav Anisovich.
In 1956 Nikolai Pozdneev graduated from the Repin Institute of Arts in Victor Oreshnikov art workshop. His graduation work was genre painting From the School, dedicated to the theme of childhood, very popular in Soviet art of middle and end of 1950s (currently in the collection of Pskov Art Gallery). In one year with Pozdneev Institute graduates Engels Kozlov, Yaroslav Krestovsky, Piotr Nazarov, Anatoli Nenartovich, Leonid Fokin, Vsevolod Petrov-Maslakov, Lenina Guley, and other young artists who later became famous Soviet painters and art educators.
Graduation picture had opened a series of Pozdneev's works of late 1950 - early 1960s dedicated of childhood theme. Among them some of his most known paintings "Spring Day" (1959), [[:|"Natasha in Baby-carriage"]] (1960), [[:|"A Fall Day"]] (1961).
After graduation, Pozdneev painted under contracts with the Leningrad branch of the Art Fund of the Russian Federation. At the same time he worked creatively, trying his hand at various genres. In 1956, he had participated in the exhibition of Leningrad artists. The very first showed his art works brought him from the Academicheskaya Dacha attracted the attention of original snapping manner of paint and the special vision of color. He painted genre scenes, portraits in exterior and interior, landscapes, still lifes, sketches from the life. In 1957 Nikolai Pozdneev was admitted to the Leningrad Union of Artists.
All the subsequent bright, brief, and dramatic fate of Nikolai Pozdneev was closely associated with the picturesque surroundings of the Academic Dacha and Tver lands. He had lived and worked in village of Maliy Gorodok in the house of his wife Vera Vasilievna. In the nearby villages lived Nikolai Timkov, Maya Kopitseva, Alexander Romanichev, Vecheslav Zagonek, Anatoli Vasiliev, Anatoli Levitin, Dmitry Maevsky, Vladimir Tokarev, and many other artists from the Leningrad and Moscow.
In 1960s and 1970s life of Nikolai Pozdneev, likes many other artists, clearly divided into two seasons: a city period from a late fall through April, and countryside period from April to November. Life in the city consisted of putting the customer and works to find new art contracts, Art Show, Artists' Union, contacts with friends and neighbours of the city art studio. Summer time at first of all is creativity, paint from the life.
Living and working at the "Academichka", Nikolai Pozdneev not only painted many of his best works, but also formed his unique individual manner thanks which his works become a phenomenon in the Leningrad Union of Artists.
Pictures painted in the late 1950s - the first half of 1960 pushed Pozdneev of the leading painters of Leningrad. Among them such works as "A Spring" (1957), "In the spring", "A Bakery", "Across the river", "Spring sketch" (all 1958), "Mushrooms. Still Life", "A Spring", "Kisharino village", "A Spring Day", [[:|"In summer at reading"]] (all 1959), "A Summer", [[:|"Natasha in baby-carriage"]], "Northern Bazaar", "A House at the road", "Grandmother's House" (all 1960), "A Summer", "Already spring", "A Porch", [[:|"Autumn day"]] (all 1961), "Baskets" (1962), "Defoliation" (1963), [[:|"Still Life in grass"]], "Shelf", "Bullfinchs", "Smoked vobla", "At the lawn", "At the aunt Sasha", "Rowan-tree" (all 1964), and others.
In 1960-1970s Pozdneev trips to Kandalaksha, Ural Region along the banks of Chusovaya River and Vyatka River, working in the houses of artistic creation in Goryachy Klyuch, Staraya Ladoga, Academicheskaya Dacha. In 1967 Pozdneev was awarded the Medal of All-Union Art Exhibition, devoted to 50th Anniversary of Soviet state. In the late 1960s and 1970s artist created the works "Before the fishing season", "At the kitchen" (both 1967), "In Art Studio", "Tea Time" (1969), "Still Life with Onions", "Still Life with Vegetables" (1971), "Houses" (1972), "Winter Landscape" (1975), "Barents Sea", "On the hill (weather station)" (both 1977), and others.
Nikolai Pozdneev died on June 10, 1978 in Leningrad in an accident at age 47. His paintings reside in the Russian Museum, in other museums and private collections in Russia, USA, France, Japan, and other countries.