The 28-year-old joined Trinity from Salford ahead of the 2015 campaign and has become a key player for Chris Chester's side.
Ashurst scored five tries in 31 appearances this year as Wakefield finished fifth in Super League.
Trinity are delighted to announce a new four-year deal for Matty Ashurst https://t.co/GDt65WLu5L pic.twitter.com/6epaeN3wcp
— Wakefield Trinity (@WTrinityRL) November 10, 2017
"I am really happy to have secured my long-term future here at Wakefield," said the St Helens academy product.
"The club has improved massively in the time that I’ve been here and that showed with us narrowly missing out on the semis last season.
"I have enjoyed working under Chezzy (Chester) and the rest of the staff and we’ve got a really good group of lads here which was a big reason I wanted to stay.
"I’m looking forward to the future and hopefully playing a part in the club building on the last couple of years and continuing to move in the right direction."
Hirst confirms the option for a further year on his contract at Trinity https://t.co/VYuoxgW2Dz pic.twitter.com/rnXcU9n5mX
— Wakefield Trinity (@WTrinityRL) November 9, 2017
Ashurst becomes the second player to commit to Trinity this week after prop Keegan Hirst extended his stay at Belle Vue.
"I am thrilled that we have been able to secure Matty for four years," said Chester.
"He has had an impressive season for us playing some big numbers week in, week out. His dedication to the club is second to none whether it is on the field or at training.
"To be able to secure a player on a long-term deal like we have with Matty proves that the club is heading in the right direction."
