26-year-old Kun Liu was killed while performing on an inflatable boat on the Ognyanovo dam in Bulgaria.
He died from wounds he suffered from an on-set explosion nearby.
His parents have filed a case of wrongful death against Millennium Films and the movie's stunt coordinator.
The Expendables 2 features an all-star action hero cast, including Sylvester Stallone, Jet Li, Arnold Schwarzenegger and Bruce Willis.
Kun Liu's parents, Zong Yu Liu and Yan Mei Bai, claim the filmmakers and Stahelski "negligently and carelessly failed to provide adequate protection from harm to the participants of the stunts".
They are suing for funeral and burial expenses as well as "the loss of society, love, comfort, attention, services and support" of their son.
Elizabeth Wolfe, a spokeswoman for Millennium Films, and stunt co-ordinator, Chad Stahelski declined to comment on the case.
At the time of Lui's death in October 2011, Bulgarian authorities reported another stuntman was seriously injured during the explosion.
Millennium films denied reports in the Bulgarian press that the doubles for stars Sly Stallone and Jet Li had been involved in the accident.
Stallone, who directed the first Expendables film and is producing the sequel, was not present at the time of the accident as he was filming scenes in another location.
The Expendables 2 is due for release in the UK on 16 August, 2012.
The parents of a stuntman killed during filming of The Expendables 2 are seeking unspecified damages from the film-makers as a result of their son's death.