I recently have had to create content types with hundred of fields. I decided to create a quick utility to generate them from a CSV file instead of using the Web interface. The application produces a module for Drupal 7.
See https://sourceforge.net/p/drupalcsvfields/code/HEAD/tree/trunk/examples/basictest/ for an usage example.
It worked for me, but use it at your own risk. I have not tested it in depth. Please backup your data before enabling the modules produced by the utility.