We arrive at 14.55 at PVG, is possible to take train to Yiwu from Hongqiao at 18.05?

Well, you can catch your train. After landing, just check out as soon as possible. Then catch the shuttle bus line 1 to Hongqiao directly within 60-70min. Or you can take Maglev to Longyang Road within 8min first and then change to subway line 2 to reach within 50min.