Personally, it is possible provided there is no delay of your flight. The train departing at 2:01 to Yiwu is train K8401/K8404 leaving at Hangzhou South train station, which is around 22km from the airport. And it takes about 35mins by taxi from airport to south station. But you would better book the tickets in advance. Or, you can stay one night in Hangzhou and take train to Yiwu on the next day.