Train takes about 4 hours or less from shanghai to yiwu.There are three Trains only take about 2 hours. There're plenty of options between shanghai and yiwu. Make sure you board a quicker and clearner one. The staff at your hotel should provide you with booking assistance. Learn more about the train from Shanghai.(Shanghai to Yiwu)
If you take bus, it leaves about every 1 hour and available at various long distance inter-province bus stations.And take about 4 hours.Some stations got more schedules than others. Make sure you know which station you are going to. Again, the hotel staff should be able to give you directions. You may want to go to either the general station ( or Ke yun Zong zhan at No. 1662 of Zhongxing Road) or Pacific Station (tai ping yang station at No. 710 Hengfeng Road.) Actually buses are just fine if you don't get car sick.
Private transportation From Shanghai to Yiwu (Recommended for group of 2 people or more)
If you want more comfort and privacy, we can also arrange private car/van pick up from Shanghai to Yiwu.