Can i buy ticket from Chadianzi to Serthar 1day before & it takes14 hours directly to Serthar,right?

Yes, you can buy the ticket one day before. But the online booking page doesn't have English version. Generally speaking, there are enough tickets. So you can buy it after arriving at the bus station.

The direct schedules from Chadianzi Bus Station are 06:10, 06:15, 06:20 and 06:25.
The ticket fare is CNY 231 per person.

Yes, duration is about 14 hours.

BIG thanks,Juana,you gave me indispensable informations to Serthar cause i'll have to walk alone there,thank you again,Juana (",)