Yangshuo bus stations

I just called Yangshuo North Bus Station and was told that there are two buses departing at 08:30 and 13:40 to Longji Rice Terrace. From there, you can transfer to Dazhai. The journey takes more than 4 hours. However, although it is available every day but the tickets can not be booked in advance and might be cancelled on the day of departure, so you need to go to the bus station early to check the availability on that day.

If it is not available, you will have to get back to Guilin and take a express bus at Qintan Bus Station (No. 31, Cuizhu Road) to get to Longsheng County. The bus departs every 40 minutes from 07:00 to 19:00. It takes around 1.5 hours and costs about CNY30. Upon arrival at Longsheng, you can transfer to bus bound for Dazhai. This bus is available every one hour from 07:00 to 17:00 and the bus fare is about CNY9. You will reach there in 1.5 hours. By the way, there are direct buses from Guilin South Railway Station to Dazhai, but it is allowed to be reserved through a hotel in Dazhai.