The best way from Hong Kong to Yiwu is by air. Guangzhou has large toy market and toy market can be found in Zhongshan Balu. Guangzhou is easy of access from Hong Kong. So, You can get to Guangzhou first from Hong Kong. If you can find what you want in Guangzhou, take a flight to Yiwu directly, or train which will take 17 hours.

from hongkong you can take a train to the Guangzhou and than change the bus to yiwu,you can find it from the infront of the Futian internationall trade b city Futian district one.

fly to hangzhou from Hongkong, then take shuttle coach from hangzhou xiaoshan airport to Yiwu directly.Yes,Yiwu is the place to buy soft toys.

by bus also can come ,and it is not expancive.