Philipp Aschenwald starts for the Mayrhofen Ski Club . He began his international career as part of the FIS Cup in two competitions on February 19 and 20, 2011 in Ramsau am Dachstein , where he finished 36th and 55th. In October of the same year, Aschenwald started for the first time in the Ski Jumping Alpine Cup in Oberwiesenthal , reaching places 40 and 48. In the course of the season and the following years, further participation in competitions in the youth field, the FIS Cup and the Alpine Cup followed.
Aschenwald started in January 2013 at the Nordic Junior World Ski Championships 2013 in Liberec , Czech Republic , where he finished 19th in the individual competition and narrowly missed the podium with fourth place in the team competition with the Austrian team. On February 9 and 10, 2013, Aschenwald finally made his debut in three competitions as part of the Ski Jumping Continental Cup in Iron Mountain, USA, and achieved a 12th, a 9th and a 19th place. This was followed by regular participation in the Continental Cup from the end of the 2012/13 season . Aschenwald celebrated a first success with a victory in Einsiedeln in the Alpine Cup on September 14, 2014. In February 2015 Aschenwald started again at the Nordic Junior World Ski Championships 2015 in Almaty, Kazakhstan . He was 18th in the individual competition, in the team competition he reached the podium with the Austrian team with a third place.
He achieved his first podium places in the Continental Cup on August 8th and 9th, 2015 in Wisla, where he took third place twice. Aschenwald then started at the Summer Grand Prix in Courchevel and Einsiedeln. He reached 14th place at both starts and won the qualification in Einsiedeln, among other things.
In December 2015, Aschenwald was nominated by head coach Heinz Kuttin for the national group of Austria at the Four Hills Tournament 2015/16 . While he failed in the qualification in Innsbruck , he made it into the second round as a lucky loser in Bischofshofen and in the end finished 29th and 49th in the overall tour with 222.9 points.
On February 9, 2019, he won the team competition on the Salpausselkä ski jump in Lahti, Finland, together with Gregor Schlierenzauer , Michael Hayböck and Stefan Kraft for the first time in a World Cup competition. At the 2019 World Championships in Seefeld in Tyrol , he won the silver medal in team jumping with his teammates Michael Hayböck, Daniel Huber and Stefan Kraft. In the individual competition on the normal hill, he narrowly missed the podium and finished fourth, while he was 13th on the large hill. He benefited from the onset of snowfall on the normal hill, which made the inrun track significantly slower after his second jump and thus hit the leaders of the first round in particular. In the final mixed team competition he became vice world champion behind the German team together with Eva Pinkelnig , Daniela Iraschko-Stolz and Stefan Kraft.