need to go to tai shan city from beihai what is the best route by bus?

It is around 500km between the two places, so it may be a little suffering to travel by bus. Anyway, you can take a long-distance bus to Yangjiang first (two buses are scheduled at Beihai Nanzhu Bus Station, leaving at 08:00 and 14:20). Then at Yangjiang General Bus Station, take a direct bus to Taishan.