Need interaction although hostkey and password already saved.

Hi,

Due to server migration I have to setup same SfTP profile as in the old server in the new one.
I have saved the host key and password into the corresponding SFTP profile account but when call it in my ssis by using the open command, it still require me to accept the host key and asked to key in password manually. Any idea what went wrong here?

You have most probably saved the site to a different local account than the one used by SSIS.
See also https://winscp.net/eng/docs/guide_schedule

In any case, you should not rely on your configuration. You better store all information into the script itself.
See also https://winscp.net/eng/docs/scripting#configuration