Piao Yinglan, who was convicted by a court in Jilin province, pleaded guilty but escaped criminal punishment as her acts "did not cause casualties or severe economic losses," state television reported.
The woman was placed in detention for 10 days after carrying out the offence, Hong Kong-based South China Morning Post reported.
Piao was a passenger on an Asiana Airlines flight from Yanji to Incheon in South Korea in February last year, the report said.
The airliner's emergency slide was also deployed after the door opened.
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The plane's emergency slide was deployed after the exit was opened.
The incident caused a four-hour delay and a direct economic loss of 34,000 yuan (USD 4,800) CCTV report said.
The report, however, did not mention why the woman opened the door.
A Chinese man was placed under detention for 15 days in August for attempting to open the emergency door and threatening to kill himself after having a row with his girlfriend when flying from Chongqing to Beijing.
In January last year, passengers on a flight from Kunming in Yunnan province to Beijing opened three emergency exit doors moments before take-off after becoming irritated with delays caused by snow.