Lawmakers endorsed Hun Manet, the eldest son of long-time ruler Hun Sen, as the new prime minister on Tuesday.
Hun Sen's Cambodian People's Party (CPP) won all but five of 125 lower house seats in the July election.
In his first cabinet meeting on Thursday, Hun Manet pledged wide-ranging economic reforms aimed at making Cambodia a "high-income country" by 2050.
"The next 25 years will be a new cycle for Cambodia," he said in a televised speech.
The World Bank defines high-income economies as those with a per capita gross national income (GNI) of $13,846 or more. According to the bank's data, Cambodia's per capita GNI was $1,700 last year.
Hun Manet said the new strategy included improving healthcare and education, as well as addressing climate change.
It also lays out a goal of "crisis-resilient economic growth of around seven percent per year on average", as well as reducing poverty rates.
Food security was also a priority, with the aim of leaving "no Cambodian citizen behind."