旅游签证能在美国多少时间？
一、按B1/B2来解释这个签证，是访问签证的一种，适用于赴美进行商务和旅游活动的申请人。这类签证没有移民倾向的顾虑，可以停留180天（半年）。二、按移民局的要求来说，要申请b1/b2是有一定要求的： 申请人必须符合以下的资格才能取得这一类型的签证。
*申请人去美国的目的是探亲或访友还是短期的游览； *申请人在美期间所从事的活动是有限的; 在申请的时候应该把旅行计划详细说明并且准备充分的资料.例如：
a)护照的有效期在回国时至少还有六个月以上； b)有足够的钱支付来回旅程及在美期间的费用（也许要在银行开立存款证明）； c)在美国没有长期居留的朋友.(也就是说不能在去了之后就在那边不回来); d)必须在前往美国之前获得有效的签证. 三、按美国使馆网站上的说法：
The B-1 and B-2 visas are for travelers going to the U.S. for business (B-1)， or for a vacation， visit， or other personal travel activities (B-2). Travelers must demonstrate that they have a legitimate purpose to go to the United States， with a plan of where they will stay and what they will do while there， and they intend to leave the country when their trip is over. The length of time someone can stay in the United States with this visa depends on his or her reason for coming here. Some people may only need to be in the country for less than six months， whereas others may want to extend their stays as long as possible by applying through USCIS for change of status to another type of legal immigration status.
This means that，只要你入境的时候理由正当，你的B1/B2是可以给你签出6个月的有效期的。 四、关于到期后的延期： 如果你在美国，你可以在入境签证有效期内进入美国并在美国停留到6个月结束前，然后就可以办理延期了： I-539 form， with application fee， should be submitted at least four months before your current nonimmigrant status expires. For example if your B-1/B-2 visitor visa expired on October 1， you would submit Form I-539 no later than February 1. If a decision is needed prior to the date it was filed， the Service may charge an additional $400 filing fee. Your spouse and unmarried children under age 21 who hold similar nonimmigrant visas may also file applications concurrently with yours. There is no provision for waiving this four month waiting period. However， some foreign consulates process visa applications within three weeks， which could allow applicants to obtain a valid extension well before their existing visas expire． Please consult our Visa Information Program (VIP）at www.uscis.gov/vip for more information regarding processing times by individual Consulates General.
另外，你也可以提前办理