您好想问下您关于未婚妻美国签证的问题呢 万分感谢！

1.假如他转了国籍 在我们结婚之前 我想去美国探望他 我应该办理旅游签证还是未婚妻签证好呢
办理未婚妻签证要求很严格，过去就必须在3个月内结婚，如果单探望的话办理旅游签吧，停留时间就不能有很长。
2.未婚妻签证有什么严格要求，需要准备什么呢，为什么很多人说未婚妻签证拒签率很高呢
你要去签证时要带的证件倒是很多，不过领事馆通知时会给你详单的。
美国政府未婚夫妻申请的官方网页

* Two (2) Nonimmigrant Visa Applications, Form DS-156 (prepared in duplicate). NOTE: K-1/K-2 visa applicants should not fill in Form DS-160, Online Nonimmigrant Visa Application.
* One (1) Nonimmigrant Fiancé(e) Visa Application, Form DS-156K
* A passport valid for travel to the United States and with a validity date at least six months beyond your intended period of stay in the U.S. (unless country-specific agreements provide exemptions)
* Birth certificate
* Divorce or death certificate(s) of any previous spouse(s) for both you and the U.S. citizen sponsor
* Police certificates from your present country of residence and all countries where you have lived for 6 months or more since age 16 (Police certificates are also required for accompanying children age 16 or older)
* Medical examination (vaccinations are optional, see below)
* Evidence of financial support (Form I-134, Affidavit of Support, may be requested)
* Two (2) 2x2 inch photographs. See the required photo format explained in Nonimmigrant Visa Photograph Requirements.
* Evidence of relationship with your U.S. citizen fiancé(e)
* Payment of fees, as explained below
3.假如我办了旅游签证，那对于我以后和老公结婚之后 再申请绿卡 是否不利呢
这个没什么影响
4.他转国籍，以及我办旅游签证，未婚妻签证分别可能要花多久呢，
主要看使领馆预约面试时间，得准备一个月左右。

办理未婚妻签证，一般是针对美国公民的，也就是你们没结婚的时候要办理签证过去就是旅游签证，你可以以你是他的未婚妻的形式办理，但是不是未婚妻签证。
未婚妻签证签过后3个月内必须结婚，然后申请临时身份，然后此可以转为公民呢。

先让他转国籍~然后结婚。
其他的都麻烦。

EFEF