The state of the art stadium, which will be the new home for Fremantle and West Coast, is due to be completed for the start of the 2018 season.
"I’m delighted to once again be at this magnificent site to celebrate another milestone delivered on schedule," Mr Barnett said.
Built over five levels, Perth Stadium will be constructed using more than 10,000 tonnes of steel and more than 52,000 cubic metres of concrete – enough to fill 21 Olympic-sized swimming pools.
Fans will enjoy more than 1,000 TV screens, two big screens and 70 food and drink outlets.
Construction will be completed by the end of 2017 to allow a transition phase ahead of the opening.
Designs of the new six-platform stadium railway station and the Swan River pedestrian bridge will be released early next year.