In a first round tie to be played on the weekend of January 15 and 16 the Trojans will host the RAF team.
The 2022 Challenge Cup sees a return for amateur teams return after this year's competition featured only professional sides, because of ongoing Covid-19 complications.
All professional RFL member clubs are invited to participate as well as a number of invited amateur teams including teams representing the British Armed forces and Police forces.
The draw for the second round followed straight after with Thornhill given familiar opponents if they can get past the RAF as they would be away to League One side Doncaster - who the Trojans played in their last tie in the competition in 2020, only narrowly losing.
The draw took place at the Tottenham Hotspur Stadium, which will host the cup final for the first time next May.
Second round matches are due to take place two weeks after the first round, on the weekend of January 29-30.
Full first round draw is:
West Hull v Upton
Featherstone Lions v Hunslet Club Parkside
Leigh Miners Rangers v Milford
Siddal v Great Britain Police
Lock Lane v Thatto Heath Crusaders
London Chargers v Ellenborough Rangers
Thornhill Trojans v RAF
Jarrow Vikings v Wests Warriors
Galway Tribesmen v Pilkington Recs
Edinburgh Eagles v York Acorn
Rochdale Mayfield v Wigan St Patricks
Bentley v Stanningley
Bridgend Blue Bulls v Royal Navy
Orrell St James v British Army
Edinburgh Eagles/York Acorn v Jarrow Vikings/Wests Warriors
Rochdale Hornets v Midlands Hurricanes
Doncaster v Thornhill Trojans/RAF
Orrell St James/British Army v Bridgend Blue Bulls/Royal Navy
Oldham v Lock Lane/Thatto Heath Crusaders
Galway Tribesman/Pilkington Recs v Siddal/Great Britain Police
West Hull/Upton v Rochdale Mayfield/Wigan St Patricks
Featherstone Lions/Hunslet Club Parkside v Bentley/Stanningley
Hunslet v Keighley Cougars
Leigh Miners Rangers/Milford v North Wales Crusaders
West Wales Raiders v Swinton Lions
London Skolars v London Chargers/Ellenborough Rangers