The attack took place during the morning rush hour, when the assailants attacked people in front of the station, the city's public security bureau said on its official Weibo microblog account.
Chen Huichao, a police officer among those injured, told Xinhua, China's official news agency, that he fired three shots and another colleague fired five shots at the suspects.
"A suspect was running from the exit of the railway station and chasing a woman and child who fell on the ground," said Chen. "It was really dangerous and we were afraid we would hurt (them)."
Police did not return CNN calls for comment.
Witnesses described a chaotic scene, with blood on the ground.
"They tried to hack me and I fended him off with my bag. Then he turned on my friend, but did not succeed in his attack," a 50-year-old man told the South China Morning Post
Another witness described seeing three people lying on the ground, with wounds to their neck, arm and head.
Zheng Sheng, a 25-year-old man, told CNN via phone messaging app WeChat that crowds of people were leaving the station at the time of the attack.
He was waiting for a friend at the station exit and said that he saw two men holding kitchen and butcher's knives.
All of the injured were taken to hospital for treatment.
Police have not revealed any details about the suspects.
The city's railway station saw a similar attack less than a year ago, when men with knives injured six people in May.
A mass stabbing in Kunming in Yunnan province shook China in March last year when attackers stormed a railway station
, killing 31 and wounding 141.
That attack was blamed on Uyghur separatists from Xinjiang. The four suspects convicted in that case had names that suggested that they were also Uyghur, a mainly Muslim ethnic group.