Thiel was born on 19 June 1913 in Oberbexbach in the Saarland, which at the time was politically part of the Kingdom of Bavaria of the German Empire.

Prior to World War II, he qualified as a civil pilot and flew with Deutsche Luft Hansa and served a flight instructor.

[2] In July 1943, Thiel was transferred to Ergänzungs-Jagdgruppe Ost, specialized training unit for new fighter pilots destined for the Eastern Front, as an instructor.

There, he was given command of the Stabsstaffel which had temporarily been led by Leutnant Herbert Friebel after Oberleutnant Diethelm von Eichel-Streiber was transferred in April 1944.

[4] Thiel was killed in action on 14 July 1944 when his Focke-Wulf Fw 190 A-8 (Werknummer 170943—factory number) was shot down by Soviet anti-aircraft artillery 2 kilometers (1.2 miles) east of Vawkavysk.