South China Morning Post said the amount of bribes involved was punishable by death but the court said it took mitigating factors into account, including that most of the bribes were taken by "designated parties" and that Sun gave investigators additional, previously unknown information about his crimes.
The Congress had confirmed the second five-year tenure for Xi, regarded as the most powerful leader of China heading the party, the Presidency and the military.
The court said the defendant had been given a lenient sentence in the light of his willingness to cooperate with the investigation.
At trial he pleaded guilty to the charges and was sentenced to life in prison, deprived of political rights for life and had the proceeds from his illegal conduct confiscated.
Sun is the latest former senior official taken down in President Xi Jinping's ongoing war on corruption. He also said he would earnestly reform himself.
Sun had been accused of taking advantage of his position to seek profits for others and illegally accepting money, according to previous court statements.
He and his alleged associates were charged with accepting the bribes in return for providing help to unspecified organisations and individuals with engineering contracts, business operations and other matters.
Mr Sun's fate was never in doubt as the party controls the courts and a guilty charge nearly always results in conviction.
"As a high-level leader, Sun Zhengcai should have set a good example", Xinhua said, but instead his corruption "damaged the normal working of government organs, corrupted the work of national government workers and undermine the reputation of Chinese civil servants". He is the fourth sitting Politburo member to be expelled from the party since 1990.
But, last year, the party's discipline inspectors publicly rebuked Sun for failing to get the job done.
Since taking power in 2012, Xi has promoted a massive campaign as a way to stamp out corruption throughout China.
During last year's National Congress, Xi vowed to continue his anti-corruption campaign, claiming "he fight against corruption has formed an overwhelming posture and strengthened in development".
His downfall came months later.