The Czech Republic International will earn over £100,000-a-week at Emirates that would make him club’s highest-paid keeper ever.
Paris Saint Germain (PSG) were reportedly ready to offer him a £150,000-a-week five-year deal, which he turned down to stay in London for family reasons.
The deal between the Blues and Gunners is expected to be rubber-stamped at the start of next week.
Cech, who spent last season at Stamford Bridge as a backup to Thibaut Courtois, believed to have wanted assurance that he will be first choice if he moves to Emirates and Arsene Wenger has agreed to the demand.
The Czech had joined Chelsea from French club Stade Rennais in 2004 for £7 million and has 12 months remaining on his current deal with the club.
He is Blues’ sixth-most capped player, having made more than 500 appearances.
Once Cech deal goes through, Arsenal are expected to sell David Ospina, who established himself as no.1 after joining the club last summer.
Turkish side Fenerbahce are rumored to be interested in signing the Colombian keeper.
Ospina’s departure means Wojciech Szczesny will remain Wenger’s no.2 next season.