After the status of lingq become 4-known, I would like to know will the flashcard delete the lingq automatically? Or I need to delete them manually?
They are not going to be deleted automatically and you would slow your progress a lot if you would choose to delete them manually because doing so is burning your bridges to the spaced repetition system. Moreover, having about a hundred of 1-3 status lingqs would not allow you to learn through noticing you old lingqs in your new texts. You need to have thousands of lingqs to do so.
@evenlaw - In addition to Eugrus’ point about the previously LingQed words no longer being available in new lessons, if LingQs are deleted/removed, they are removed from the SRS system which will otherwise send them back at you 15 days, 30 days and 90 days after to make sure you do know them. Also, deleted/removed words are no longer included in your Known Words statistics and Learned Words statistics.
I would support what eugrus had to say. The first emphasis should be on creating lots of LingQs, more than you could ever find the time to delete or move to known.
Ok, thank you everyone answering, I have known the lingq system better 