from hangzhou train station to westlake 7 service apartment xihu how to go

Are you mean the apartment in A-726 Dongfang Jinzuo, 1 Yuewang Road (Yuewang Lu) ?
Take Subway Line 1 to Long Xiang Qiao (Longxiang Bridge), and then walk to your apartment. You can get off from exit D4, walk along Pinghai Road to the east until you see Labor Union Building, from the next crossroad near the building turn to south, walk about 100 yards you’ll see it.