Malcolm last night finished second in 20.63secs at the Olympic Trials 200m in Birmingham. It was enough for the 33-year-old to book his place in the team for London 2012.
Malcolm, who finished fifth in two Games finals in Sydney and Beijing in 2000 and 2008, suffered injury in 2009 and had his funding cut.
But the Newport sprinter battled back to win medals at the European Championships and Commonwealth Games in 2010 and has continued his upward curve.
“I am honoured to be going to a fourth Olympics,” said Malcolm.
“This is an extra special one because it is at home.
“There was a time in 2009 when I wondered if this was going to be possible when I had injuries and there were funding issues.
“But I have battled back and I would thank everyone who has supported and backed me.”
Malcolm followed up his fifth place finish in Saturday evening’s 100m with his 200m silver medal with his Great Britain place guaranteed because of his A standard achieved earlier in the season.
“I’m so pleased and my experience got me through this weekend,” added Malcolm.
“I said that this weekend was all about qualifying. I always like the double but it was a bit of a gamble .
“If you can put five hard races like that back to back then you’ve got some good training that will prepare you for the major champs.
“But I have never felt as drained as I do now after a British Championships weekend.
“I was on the start line trying to get hyped up and inspired.
“It was a surreal moment because I had the devil on one shoulder telling me to give up and go to bed and the angel getting me inspired on the other shoulder.
And Malcolm insisted he would be in better shape when it came to London.
“I have had a good winter’s training and I know I am in better shape than the times I have run this weekend,” he added.
“For me I always keep in good shape for the major championships and I thrive on this environment.”