回复：回复：回复：我最关心的是第一个问题，如果每5个月回美国一次，是不是能keep自己的连续居住时间的记录。

You got it right.
When you file for n-400, you will need to fill in white and black how many days have you been outside US and for what purpose, along with n-400 you are required to send in 3 or 5 years of tax transcript.  Your plan doesnt' sound very promising if you want to claim your citizenship in a couple of years while you are away.