Thanks for your help. Since I do not know much about bitcoin advance technique, how can I get the private key of this address?
As I said, your addresses do not just map to one private key, they may have multiple and have a script, so it is much more complicated.Did you setup your wallet as as multisig wallet or are you using 2FA with your wallet?
Do you still have access to the seeds used for this wallet. 2FA uses multisig for the wallet. Are you unable to use the 2FA which is why you are trying to get the private key or do you need it for another purpose. If you still have the seed, you can restore the wallet for use without 2FA by following the below steps.
Your seed contains two master private keys in a 2-of-3 security scheme. In addition, the third master public key can be derived from your seed, ensuring that your wallet addresses can be restored. In order to restore your wallet from seed, select “wallet with two factor authentication”, as this tells Electrum to use this special variety of seed for restoring your wallet.
Note: The “restore” option should be used only if you no longer want to use TrustedCoin, or if there is a problem with the service. Once you have restored your wallet in this way, two of three factors are on your machine, negating the special protection of this type of wallet.
