You can take the bus directly to CUHK, then take the school bus directly from CUHK and get off at the south of CUHK. The specific school bus schedule can be inquired and confirmed in official website, south of CUHK.

The above is more convenient, but if the time doesn't agree, you can only take the bus at the station. You can check whether there is a bus from Zhongshan to Conghua Bus Terminal, or take a bus to Guangzhou to Conghua Bus Terminal, and then sit at Conghua Bus Terminal. There are two choices at the bus station, one is the school bus to Zhongda South, and the other is the bus passing through Zhongda South, both of which can be bought at the last ticket window. You can ask the bus that sells tickets and decide which bus to take. The latter needs to get off at Zhongda South Archway.

So now there are three routes.

Zhongshan 1- liberal arts building of zhongda south campus-(school bus) zhongda south

2. Zhongshan-Conghua Bus Station (bus)-South Pailou of Zhong Da University-South of Zhong Da University

(school bus)-Zhongda South

3. Zhongshan-Guangzhou-Conghua Bus Terminal (Bus)-South Pailou of Zhong Da University-South of Zhong Da University

(school bus)-Zhongda South

I have graduated. I don't know if there will be new ways or changes, but I am very close. I hope I can help you.