During the Yuan Dynasty, many people suffered under the rule of the Mongols. Zhu Yuan-zhang decided to lead his army against the Mongols, but his plans failed because he could not send messages to his people who were living inside the city.

Zhu Yuan-zhang said,“I cannot succeed alone. It would be much easier to defeat the Mongols if my people could help me from within the city walls.” His advisor Liu Bo-wen thought of an idea. He told Zhu Yuan-zhang,“Just hide the message inside mooncakes, and let everyone bring home a mooncake. Then, all of your people will get your message.”

Zhu Yuan-zhang ordered his men to hide this message inside the mooncakes:“Revolt on the night of 15 August”to make sure everyone got a mooncake, Liu Bo-wen spread this rumor:“There will be a catastrophe this winter, but if you eat mooncakes, you can prevent it and be safe. So, the people who ate the mooncakes got the hidden message, and slowly, everyone in the city got the message. On the night of 15 August, the people revolted and defeated the Mongols.

After that, people would eat mooncakes on 15 August to celebrate the victory of their ancestors. This is how the custom of eating mooncakes came to be passed down for generations.

在元朝的時候，人民因為蒙古人的統治，生活變得十分困苦。朱元璋帶領軍隊攻打蒙古人，卻都因為消息傳遞不易，無法團結所有人民的力量而失敗。因此，朱元璋說：「光靠我一個人的力量是不夠的，如果可以和人民一起團結的話，這樣要成功就容易多了。」劉伯溫就想了一個辦法，告訴朱元璋說：「只要把訊息藏在月餅裡頭，然後傳遞給大家，這樣一來，就可以讓所有的人民知道這個消息了。」

朱元璋便下令將字條藏在月餅裡，裡面寫著：「八月十五夜起義。」為了讓月餅可以送到每個人的手上，劉伯溫就派人散布謠言說：「今年的冬天將會有一場災難，只要吃了月餅之後，災難就可以解除了。」於是，那些吃了月餅的人們，果然發現了月餅裡的訊息，漸漸的所有城裡的人都知道了這個消息，到了中秋的夜晚，人民便團結起來打敗了蒙古人。

後來，在每年農曆八月十五日這一天，人民都會吃月餅來紀念這件事情，而吃月餅的習俗就這樣子流傳下來了。