Double European champion Barker, 18, improved on last year’s silver at this event with a time of 22 minutes and 26.29 seconds on the 15.6km course.
Barker has also won several world junior track medals and is widely regarded as one of the hottest prospects in British women's cycling.
Denmark’s Cecile Ludwig was second 35s back with Demi de Jong of the Netherlands a minute behind in bronze.
1. Elinor Barker (Great Britain) 22:26.29
2. Cecilie Ludwig (Denmark) +35.87
3. Demi De Jong (Netherlands) +1:03.13
4. Emily Roper (Australia) +1:08.18
5. Ramona Forchini (Switzerland) +1:10.42
6. Eva Mottet (France) +1:11.59
7. Christina Siggaard (Denmark) +1:13.26
8. Coprinna Lechner (Germany) +1:13.35
9. Nicky Zijlaard (Netherlands) +1:14.84
10. Lourdes Oyarbide (Spain) +1:15.26