Steinhoff 1910-1921 studied law at the universities of Freiburg, Munich, Königsberg, Berlin and Münster and in 1921 Dr. jur. doctorate. By 1923 he was in the Reich Ministry of the Interior and Justice, to 1924 as Secretary of Legation of the Saxon legation in Berlin, until 1926 as a council in the Amtshauptmannschaft Zittau until 1928 as a district administrator in Zeitz and then as Government Vice- President of the governmental district Gumbinnen / East Prussia and Vice - Governor- operating from East Prussia in Königsberg.
From 1923 he was a member of the SPD. In 1932, he was suspended and dismissed in 1933 from the civil service. 1940-1945 he was General Counsel of a cardboard wholesale business in Berlin. In 1945 he was president of the Provincial Council and from 1946 to 1949 Minister President of Brandenburg and member of the Brandenburg state parliament, then to 1952, Minister of the Interior of the GDR. His dismissal was prompted by Walter Ulbricht.
Since 1922, Steinhoff was a member of the SPD and advocated in 1946 - in the belief that unity of the SPD and KPD could have prevented the power of Adolf Hitler - the merger of the KPD and SPD in the Soviet Zone to the SED. Steinhoff was 1948-1949 Member of the German People's Council and until 1954 deputy of the Provisional People's Chamber, 1949-1950 member of the Political Bureau of the Central Committee of the SED and 1949-1954 Member of the Central Committee of the SED. 1949-1955 he was a professor of administrative law at the Humboldt University in Berlin, then in Bezirksfriedensrat Potsdam operates.
Steinhoff received the Patriotic Order of Merit, the honor Clasp to the Patriotic Order of Merit and the Order of Karl Marx.
- Alfredo Panzini, Francesco Pastonchi: Italian novels. Translated by Carl Steinhoff. Märki shear Verlag, Wilhelmshorst 1997, ISBN 3-931329 -02- X ( with CV written by Steinhoff's son Rudolf and contribution of Hans- Joachim Bach horror of the situation in Brandenburg 1945-49)