Guo Boxiong, 74, was accused of using his influence to seek promotions for others and of accepting bribes.
He was stripped of his rank of general and his personal assets have been seized, Xinhua news agency reports.
President Xi Jinping has led a major anti-corruption campaign since taking office nearly four years ago.
Hundreds of thousands of officials have been disciplined as part of the drive.
From 2002 until 2012, Guo served as vice-chairman of China's Central Military Commission, which is in charge of the People's Liberation Army - the world's biggest armed forces.
During that time he had also been a member of the 25-person Politburo - the power-base of the Communist Party.
The Communist Party expelled him last year following a corruption probe.
Guo's trial was held behind closed doors and Xinhua did not disclose the amount of money involved.
But sources told the South China Morning Post in April that Guo was prosecuted for accepting bribes worth $12.3m (Â£8.6m).
The paper reported that this was thought to be a small fraction of the wealth actually amassed by the former general, who was one of the most senior officers to serve under former President Hu Jintao.
Guo had admitted his crimes, expressed regret, accepted the judgment and would not appeal, Xinhua said.
For many in China, details of the former general's crimes will barely raise an eyebrow.
Guo Boxiong profited far less than some of his Communist Party colleagues. When police raided the home of Zhou Yongkang, the former domestic security chief and a contemporary of Guo, they seized $14bn in assets.
Many believe the retired army general's true crime was his allegiance to the former Chinese president, Jiang Zemin, and not the current leader, Xi Jinping. Guo was promoted through the ranks under Jiang Zemin and is thought to have maintained close ties even after he left power.
Xi Jinping has repeatedly called on troops to pledge their allegiance to the Communist Party, and its chairman and head of the military - himself. Dozens of senior military officers have been purged through the ongoing anti-corruption probe and replaced with officers who owe their careers to Mr Xi.
As the Chinese leader attempts to cultivate a leaner, cleaner military loyal to him, the case of Guo Boxiong could serve as a warning to all new recruits.
"Corruption is the greatest threat our party faces, and is the top killer of the military's fighting ability," the Reuters news agency quoted the defence ministry's website as saying.
The case follows that of another top general, Xu Caihou, also accused of taking bribes in exchange for assisting in promotions, but who died last year before a trial.
State media reported that it had taken a week to catalogue all the cash, jewels and antiques amassed in Xu's Beijing residence, and that 12 trucks had been required to remove them all.
Guo's son, a major general, is also under investigation for corruption.
A retired high-ranking military officer in China has been sentenced to life in jail by a military court for corruption, state media report.