How to get by subway from Hengshan station to 900 ZhongShan Xi Lu, Shanghai?

Do you refer to Hengshan Road Metro Station?
If yes, there is no direct metro between these two places. You can take the train from Hengshan Road to SH Indoor Stadium Station. Then transfer to line 4 to SH Stadium. After arriving, walk to the destination directly.

Or you can take public bus no.49 to South Urumqi Road, Hengshan Road Station, and get off at Zhongshan Naner Road, South Wanping Road. Then walk to the destination.