During the Second Silesian War, Münchow participated in the Siege of Prague in September 1744 and the Siege of Cosel and in the Battle of Hohenfriedberg. There, on the left wing of the first meeting with the regiments Borcke, Blankensee and Bevern, he held the position until the attack of the Bayreuth Dragoons decided the battle in favor of Prussia. On 15 July 1745 Frederick promoted him as lieutenant-general. For his actions in the Battle of Kesselsdorf, the King awarded him the Black Eagle Order in December 1745. In August 1747 he became governor of Spandau.