Now, there are two trains everyday from Beijing to Beizhai Station, the nearest station to Mutianyu. 6:16 and 16:43 from Beijing North Train Station (Xizhimen Train Station) and back from Beizhai at 12:29, 18:55. The train ticket is 6RMB for hard seats and 11RMB for soft seats. It takes 2 hours on the train.

thanks mr. qi. how far is beizhai to mutianyu? and is it easy to spot the bus that'll take you there?

It is still 14km from Beizhai to Mutianyu. So, train is not best way. During the Golden Week, generally from Sep 18-Oct 7. there is direct bus 936 from Dongzhimen to Mutianyu directly.

yeah. it might not be the best way. i was just worried that i would hop in to the wrong bus. btw, how long's the travel time via bus?

I am afraid 2-2.5 hours by bus 936. Another problem is that there may be a long waiting line at the bus station. You can consider to take the train then taxi. If you travel with others, you can talk about hiring a taxi or van to and back.

appreciate it Mr. Qi. I couldn't take u enough on these info you've shared.

In former years, there are usually tour trains go from Beijng to Mutianyu during golden weeks, But I have not heard about it this year.
The most convenient way from Beijing to Mutianyu is taking tour bus no.936 at Dongzhimen Outer. It will take you directly to the scenic point. The bus departs at 0700 and 0800 Mon-Fri and 0700, 0800 and 0900 on weekends; from Mutianyu at 1400 and 1600 Mon-Fri and 1400, 1500 and 1600 on weekends.
There are many kinds of bus no.936, you should ask the driver if the bus is heading for Mutianyu Great Wall before boarding. Take the one equipped with card reader, otherwise the bus will be a private one and you may get cheated.