Sun's sentence, handed down by the intermediate court in the northern port city of Tianjin, appears to end a career that had once been seen as propelling him to the apex of power in the ruling Communist Party.
The court said the defendant had been given a lenient sentence in the light of his willingness to cooperate with the investigation.
At a party meeting past year, a senior official stated that Sun and other senior figures prosecuted in Xi's anti-corruption crackdown were "conspiring openly to usurp party leadership".
Sun had been elevated to the party's elite 25-member Politburo and was the top official in the western megacity of Chongqing before suddenly being removed in July.
Sun Zhengcai, 54, a former political high-flyer once tipped to be among China's next generation of leaders.
Sun had been accused of taking advantage of his position to seek profits for others and illegally accepting money and property during several positions held by him including as Minister for Agriculture, according to previous court statements.
Xi has been promoting a massive anti-corruption campaign since he came to the office in 2012. Shortly after the investigation was announced, Mr. Xi promoted a protégé, Chen Min'er, to take over as party chief in Chongqing.
In March, China's parliament scrapped presidential term limits, paving the way for President Xi Jinping to rule indefinitely over the world's most populous country.
Chinese news outlet Caixin had reported that Sun's "designated parties" included two businesswomen.
Sun's case is interesting because it seems to signal that any challengers can be charged with a political crime.
He was the youngest member of the Politburo before he was expelled and was once widely considered a strong candidate to sit on the Politburo Standing Committee, the Chinese leadership's inner sanctum. Both are serving life prison terms after being convicted of corruption or other misconduct.