Efim studied at the Borisoglebsk progymnasium and Moscow University.
In the mid-1890s, he collaborated with the journal Novoe Slovo. For participation in student organizations, he was arrested and then was under the supervision of the police. He ran a mill in Borisoglebsk, built a steam mill at the station Ternovka, Borisoglebsky uyezd in the 2nd half of the 1890s.H e was one of the founders of the Borisoglebsk Public Library in 1897, which he made donations, and its member of the committee In the early 1900s he was a chairman of the Borisoglebsk stock exchange committee, a member of City Duma. In 1902-1905 he successfully worked in the milling industry in the city of Harbin. In 1905-1906 Efim Dmitrievich founded the publishing houses ‘Kolokol’ and ‘Young Russia’ in Moscow, which produced Social Democratic and Socialist-Revolutionary literature. People’s House in Borisoglebsk(1909–1915) was built at the expense of Myagkov, now the building of the N.G. Chernyshevsky. In 1916 he was in Serbia as a correspondent of the newspaper Russkoye Slovo. In 1918 he was the head of People’s House in Borisoglebsk, then he was forced to move to Moscow.
Efimwas married to Olga Alexandrovna.