Suarez was handed the ban for racially abusing Manchester United star Patrice Evra.
Poyet told Ultimas Noticias newspaper in Uruguay: "The ban is incredible, shocking, it's disproportionate. I back Luis to death.
"Things have happened before with Evra. He is not a saint. He is a controversial player.
"I don't know in which world we are going to live in from now on people. People will accuse each other of anything.
"Suarez just arrived [in the Premier League] and there are things that he has to learn when you are in another country because they might be normal in your country but perhaps they are not considered that way in other parts of the world.
"I have tried to explain that we live with coloured people in Uruguay. We share different experiences with them. We play football, we share parties. We are born, we grow up and we die with them. We call them 'blacks' in a natural way, even in an affectionate way. That is the way we were brought up. We are integrated and there are no problems from either side.
"I've explained how the Uruguay people and the South Americans experience these situations with coloured people. I've been many years in England and I understand them. I know how to deal with it, but Luis has only recently arrived here."