Tousard was educated at the Royal Engineering School of Mézières. In 1770 he became a lieutenant, and was promoted to captain fourteen years later in 1784.
In 1799, he took part in the expedition into Syria, and was responsible for various works in Gaza and Arish. He was appointed Chef de Brigade on 5 February 1801 by General Menou. This rank was confirmed in France on 7 February 1802. On 11 December of the same year, he became director of fortifications.
In 1803, he joined the Armée d'Angleterre for the planned invasion of England. He became a Knight of the Legion of Honour on 11 December 1803, and became an Officer on 14 June 1804. From 1803 to 1805 he was deployed as an engineer at Bruges, Ostend and Ambleteuse.
Tousard was assigned to the 3rd Corps of the Grande Armée on 30 August 1805. He was captured in Neuburg in October 1805.
He was promoted to brigadier general on 5 July 1807, and was in control of the engineering of the 3rd Corps stationed in the Duchy of Warsaw between 1808 and 1809. He became Baron of the Empire on 16 September 1808. Tousard was seriously wounded on 3 June 1809 while repairing a bridge in Linz.
On 3 August 1810, he became a member of the fortifications committee, and was responsible for an inspection tour of the fortifications in the 32nd military division. In January 1813, he assumed the same functions in the 31st and 32nd military divisions.
He was sent to Hamburg on 15 August 1813, and he died there on 15 September, at the age of 60.[3]
^ abSpiteri, Stephen C. (26 December 2011). "Fort Tigné - 1792 - Part I". MilitaryArchitecture.com. Archived from the original on 17 August 2016. Retrieved 23 June 2015.