What you want to ask is why you can't sign with your mobile phone when your mobile phone is turned off? The reasons are as follows.

1. After the phone is turned off, the internal circuit of the phone no longer works, and it cannot provide the power and resources needed for power supply and running programs.

2. The mobile phone screen can't display any information. The signer needs to wait until the phone is turned on before signing.

3. Sign through the signature software installed on the mobile phone or the network signature platform.