The accident occurred in the braking area near the finish, but officials didn't release any details of what happened, USA Today reported.
The worker was struck by a forerunner sled, which goes down the track before competitions to test the timing system and track conditions, NBC News reported.
The accident happened in Krasnaya Polyana at the Sanki Sliding Center, the venue for bobsled, skeleton and luge events at the Sochi Olympics, just before training for two-man bobsled was to begin, NBC News said.
"The worker is undergoing surgery for two open fractures in his legs," said International Olympic Committee President Thomas Bach.
Bach said the worker was conscious when he arrived at the hospital.
"We're pretty relieved," Bach said. "There is no danger for life."