Second-half goals from Etienne Capoue, Christophe Jallet and Franck Ribery put paid to the Belarusians and sent France top of Group I ahead of their 16 October showdown with world and European champions Spain in Madrid.
Deschamps was overseeing his first game as national coach at Stade de France, the stadium where he led Les Bleus to victory as captain at the 1998 FIFA World Cup, and he was pleased to have marked his return with victory.
"It's always a very good evening when you win," said Deschamps. "And it's becoming rarer and rarer to score three goals at the highest level, so you have to savour it."
With France having won 1-0 in Finland in their opening game on Friday, Deschamps' side are three points clear of Spain, who began their title defence with a narrow 1-0 win over Georgia on Tuesday.
Deschamps has built his managerial reputation upon a pragmatic approach to winning matches and he emphasised his belief that wins at international level cannot be taken for granted.
"Spain's great team only won 1-0 in Georgia," he said. "It's difficult for everyone. We should savour these six points, but it's a reward for the general spirit. The players feel good together. That's only background noise if you don't see the result on the pitch, but there's a collective desire to make an effort and to hassle (opposition players)."
Against a Belarus side ranked 76th in the world, Deschamps opted for a slightly experimental 4-3-3 formation that saw Ribery aligned next to Karim Benzema and Olivier Giroud in a lopsided attacking trident.
Benzema began the game in an unfamiliar right-wing role, but displayed plenty of confident touches and although he did not score himself, he did set up Ribery for a coolly taken goal in the 80th minute. "He was out of position," said Deschamps of Benzema's new role.
"I know he's not an out-and-out winger, but in order to make Giroud the focal point, Karim made lots of effort in the build-up. He made an effort in defence as well. It seemed to me the best solution to cause them problems."
Deschamps also praised Toulouse midfielder Capoue, who came into the team for the injured Abou Diaby and opened the scoring in the 49th minute to mark his first France start with his first international goal.
"He was playing in a different position to at Toulouse," said Deschamps of Capoue. "He has quality and he was rewarded tonight, but the most important thing is the team. We'll remember his first goal for the national side.
"He's not comfortable with his back to goal, but he got himself forward and that's what I'd asked of him. He's not there to be a number 10 and he doesn't have 50 caps either. I won't ask any more of him."