In 1973 he was elected as deputy secretary committee of the Komsomol on ideological educational work at the Leningrad Mining Institute.

Mironov has several times proposed an amendment to the Russian constitution that would allow the President to be elected for 3 consecutive five or seven year terms.

[5] In January 2023 he posted a photo of himself posing with a sledgehammer branded with Wagner Group logo atop an engraving of a pile of skulls.

[8] In late 2022, Russian opposition politician Nikita Yuferev accused Mironov of violating Russia's 2022 war censorship laws.

Mironov's project was preceded by a successful action to collect a million signatures against payments for capital repairs until the state fulfilled its obligations to citizens.

[29][30] Mironov is a supporter of the experimental method of TNVR (Trap–neuter–vaccinate–return), legalizing the free presence of stray dogs in the urban environment.

In November 2018, he initiated, together with deputy Vladimir Burmatov, a bill allowing the return of these animals to the streets of cities after sterilization.

[31] By decision of the Supreme Court of the Russian Federation in January 2017, the TNVR method was banned in the Rostov Oblast as not complying with the current legislation in the field of ensuring sanitary and epidemiological well-being of the population and prevention of contagious diseases,[32] and in October 2018, the City Court of Saint Petersburg banned TNVR in this subject of the federation as well.

The explanatory note to the bill states the need not to limit the regions in their authority to treat these animals, suggesting that they should be guided by humane considerations and not depend on the position of courts and veterinarians on this issue.

[33] In July 2018, Mironov had already proposed a similar bill, according to which "all stray animals that have been sterilized and vaccinated should be released in the same place from which they were taken by specialists".

At the same time, sterilized dogs will still have aggression towards humans and other animals, they will continue to fight for food and territory, and they will still be potentially dangerous.

An investigation by BBC News found that in 2022 Mironov and his wife had adopted a 10 months old girl Marharyta Prokopenko that was abducted from Ukraine's town of Kherson by Inna Varlamova during Russian occupation to Moscow under the pretext of "medical examination".

According to The Insider in a report published in January 2022, Mironov's family owns an elite apartment in Moscow worth 350 million rubles, which is almost 70 times more than the politician's officially declared annual income.