A method for supervising a flight state of an unmanned aerial vehicle includes establishing a communication connection with a control terminal of the unmanned aerial vehicle, and receiving and storing an off-line flight certificate sent by the control terminal. The off-line flight certificate includes off-line flight parameters. The method further includes monitoring and restricting, in response to the unmanned aerial vehicle being in an off-line flight mode, a flight behaviour of the unmanned aerial vehicle in the off-line flight mode according to the off-line flight parameters in the off-line flight certificate.