i m arring at 1150pm at shangai airport and going to yiwu which one is cheap train or bus?

Which airport will you arrive at?
According to your arrival time, both airports don't have public transportation that can take you to Yiwu. So you have to start off in the next day.
If it is Hongqiao Airport, there is no direct train or bus that can take you to Yiwu. You are suggested to take subway line 10 to Hongqiao Railway Station first. Then take high-speed trains to Yiwu. This way is an economical and convenient way. The ticket fare of first class seat is CNY202 and second class seat is CNY123.

If it is Pudong Airport, you can take a direct long-distance bus to Yiwu, ticket fare is around CNY 180 per adult. If you want to save money,you can take shuttle bus or subways to SH General Bus Station first, and then take long-distance bus to Yiwu; in the way, the long-distance bus ticket fare is CNY 96 per adult.