Cao was later charged with murder, although it took police more than a year to find her remains, in an area of private farmland in the Greenpark area south of Christchurch.
The trial, before Justice Lisa Preston, is expected to last up to six weeks.
Cao is being represented by defence counsel Colin Eason, while prosecutor Pip Currie will present the case for the Crown.
Bao’s family earlier issued a statement thanking family, friends, and the general public for the “outpouring of kind words and unwavering support following the disappearance of their beloved wife and mother”.
“The love and compassion displayed by fellow New Zealanders has been truly humbling, and the Bao family cannot express how grateful they are for all the generous donations made through Givealittle,” they said.
The family also expressed their “sincere appreciation” to the police for their “invaluable support and relentless dedication” in the search for Bao.
After Bao’s remains were found in July this year, Detective Inspector Nicola Reeves, who headed the extensive police investigation, spoke of the relief that she had finally been located.
“This news brings to a close a key aspect of our investigation and Yanfei will now be returned to her family,” Reeves said.