http://wikitravel.org/en/Hallstatt#Get_in    By Train
From the main line between Salzburg and Vienna, get off at
Attnang-Puchheim. Take a train from here towards Bad Ischl and
Obertraun. The Hallstatt station is south of Bad Ischl and one stop
north of Obertraun; it is on the east bank of the Hallstättersee
(Hallstatt Lake) and consist of just a boat dock next to the tracks. A
regular ferry service will meet each arriving train and take you to the
town across the lake. One of the best views of Hallstatt is from this
ferry ride across the lake, especially in the morning when the sun is
shining on the town.

When leaving, the boat takes you back to the tiny train station,
where you may take the train back to Attnang-Puchheim and transfer to
your next destination. The boat meets each train leaving the station,
and the schedule is posted at the boat dock, or it also is available at
tourist information. The tourist information office can provide further
information about train schedules since the train station itself is
likely unmanned (and it is across the lake). You can buy the ticket on
the train, but only with cash. It is better to buy your next ticket in
advance, if possible. Once on the train, ask the conductor if he/she
knows the platform number of your desired transfer (don't worry, all
train employees speak English), or check the departures screens when you
get to Attnang-Puchheim. But be prepared, the transfer may be fast, as
Attnang-Puchheim is not a big station, and the passing trains will not
stop for long.

[edit] By bus
Shuttle Cesky Krumlov (Door-to-door shuttle from/to Hallstatt), ☎ 00420 607 963 868 (info@shuttleceskykrumlov.com), [3]. offers door-to-door transportation between Hallstatt and Salzburg, Linz and Český Krumlov.  edit
Bean Shuttle (Cheapest shuttle between Hallstatt and Cesky Krumlov), [4].
offers direct shuttle bus between Hallstatt and Cesky Krumlov for 800
CZK (35 EUR) per person and between Hallstatt and Ceske Budejovice for
900 CZK (39 EUR). €35.  edit
CK shuttle [5] and Budweis-shuttle [6]
offer a door-to-door transportation service from Český Krumlov to
Hallstatt and back for 1.100 CZK (44 EUR) pro person. The ride takes
about three hours.
Czechshuttle.cz (Shuttle bus from / to Cesky Krumlov), [7]. 2.5 hours.
offers door - to - door Shuttle bus to Hallstatt) from Cesky Krumlov
and back.Price 1050 CZK (42 EUR) per person.) Private transportation
available by CAR or VAN €.  edit

By taxi, or car. A street passes through a tunnel in the mountain above the town. There is underground parking available here.

真的就是没有，但是查时刻表的时候又有，直接买票就跳出来说没有，怎么回事呢，是不是时间太早？

起点Hallstatt，终点Wien，需要转1次车，不会没有这个行程的。