is 30000mah power bank allowed in flight

not allow
It is not allowed to use a 30000mah portable power bank during flight.
The Civil Aviation Administration of China has made relevant regulations on carrying power banks on airplanes. Power banks with a rated energy of less than 100Wh can be carried on airplanes, while power banks with a rated energy between 100Wh and 160Wh require the consent of the airline before they can be carried on airplanes. And power banks do not directly indicate the rated energy, only the capacity. So only through conversion can we know how much capacity a power bank can carry on a plane