According to the Civil Aviation Administration of China (CAAC), a man carrying a fountain pen threatened to harm Air China staff members on board the plane, forcing the aircraft's pilots to take action.
As the channel CGTN, the plane made flight from Changsha to Beijing.
An Air China flight had to be diverted after a passenger held a crew member hostage using a fountain pen as a weapon.
The city's airport described the reason for the diversion as "illegal interference", adding that other passengers were in a stable mood and the airport was operating normally.
It said only that "the matter was successfully handled" by 1:17pm, but did not provide any details.
"The man onboard flight CA 1350 had a sudden [flare-up] of mental illness when he held a flight attendant hostage", the Henan public security bureau clarified in a statement on Chinese social media website Weibo.
It identified the man only by his surname, Xu (徐), and said he was 41 and from Anhua County in Hunan. However, China has been fighting growing dissent from a wide variety of groups including political, religious and regional breakaway factions.
According to the aviation authorities, by 13.17 local time the situation was settled.
All passengers, except the suspect in the attack, left the plane.
The passenger stated that looking out the window they saw many police cars, ambulances and fire engines parked outside the plane as it was landing in Zhengzhou.