The Cameroon international joined the Catalan club last summer for £15 million after failing to pick up any trophies at the Emirates.
Wenger's future has been surrounded by speculation this season with a number of clubs showing an interest in adding him to the helm of their club.
Song insists that the Frenchman though is the right man to stay in charge of the north London club and should ignore interest from the likes of PSG and Monaco to continue with his project.
Song said: "I spent eight years with him and he's just unbelievable. I still keep in touch with him and the last time I met him he was very happy.
"Hopefully he'll stay longer at Arsenal because if they lose him today then they won't be the same."