Its going to be a heavily modified up rated Mi-26.
China Defense Blog: The Sino-Russian 20+ ton Heavy-lift Helicopter Project, confirmed
"Aleksandra Mikheyev, general manager of the Russian Helicopters, said at the Zhuhai Air Show in November 2014 that the contract would be signed for the China-Russian heavy helicopter joint development project in two or three months, and the aerodynamic configuration and flight performance parameters of the helicopter would be determined by February 2015.
Mikheyev said that the model is evolved from the M-26T helicopter, its take-off weight and carrying capacity are all smaller than those of the M-26 helicopter, but it is equipped with the M-26's D-136 engine, and therefore is superior to the M-26 helicopter in terms of thrust-weight ratio and mobility.
The latest coverage of the Russian media, however, described the helicopter as "with a take-off weight of 38 tons and a carrying capacity of less than 15 tons, it can be used on plateaus under thermal climate conditions", which is not a copy and simple improvement of the M-26 helicopter."