@Raze, Many thanks for your patient reply!
For any new saving at any condition,loading it will caused a crash. I have an earlier save, after loading it,I can only saved normally a few times ( I remember about 3~4 times), then further new save will be the same result.
Ok,I have emailed the save file. Now I deleted all and reinstalled the DD, restarted a new journey from Aleroth!