回複：如果我用B1遞交的話，必須在美國呆滿三個月，對嗎？

how many times have you used this B visa to enter US? If only the first time and your real intention is to stay until you get GC. yes, it's better to wait until 3 months (since entry)
If you come and leave US using this B visa severy times already, you can file I485 anytime after your entry without worries.