Zeng Cheng started his professional football career at top tier club Wuhan Guanggu, however he was soon loaned out to Indonesian football team Persebaya Surabaya for more playing time at the beginning of the 2005 season. On his return to Wuhan, he would be allowed to make his league debut at the end of the league season on 5 November 2005 in a 1–1 draw against Shanghai Shenhua. For several seasons, Zeng would play understudy to Deng Xiaofei until Wuhan quit the league and were subsequently relegated in the 2008 season after the club's management did not accept the punishment given to them by the Chinese Football Association after a scuffle broke out during a league game against Beijing Guoan on 27 September 2008.
At the beginning of the 2009 season, Zeng transferred to another Chinese Super League team [[Henan Jianye F.C.|Henan Jianye], where he was immediately chosen as first choice goalkeeper ahead of existing goalkeeper Zhou Yajun. The move turned out to be a big success and the club would finish in it highest ever position of third within the league and qualify for the AFC Champions League for the first time in the club's history.
On 1 January 2013, along with Zhao Peng and Yi Teng, Zeng successfully transferred to two-time, back-to-back Chinese Super League champions Guangzhou Evergrande on a free transfer. During the 2013 season, Zeng established himself as Guangzhou's number one goalkeeper due to impressive displays which impressed manager Marcello Lippi. At the end of the season, Lippi credited Zeng as "one of Guangzhou's best buys." Zeng finished the 2013 season only conceding 16 goals and kept 13 clean sheets in 27 matches in the league. He was an important cog in what was considered absolute dominance by Guangzhou during the group and knockout stages of the AFC Champions League that season. On 9 November 2013, Zeng won the continental title with the club, winning the finals against FC Seoul in a two-legged tie which ended with them winning on away goals.
Due to his impressive performances at the beginning of the 2009 season, Zeng was called up to the Chinese national football team by then manager Gao Hongbo. He made his debut against Iran in a friendly international,which China won 1–0 on 1 June 2009. After that game, he would become the national team's second choice goalkeeper behind Yang Zhi and be included in the squad that won the 2010 East Asian Football Championship before being included in the 2011 AFC Asian Cup squad. On 3 June 2012, Zeng was the goalkeeper between the posts against the world and European champions Spain. Even though they lost 1–0, Zeng Cheng still made exceptional saves to prevent an even worse defeat. On 11 June 2013, Zeng played against the Netherlands and only conceded two goals, one from a penalty, which saw him perform many important saves.