The 20-year-old rider beat about 5000 other hopefuls to win the ride.
Her quest started when she entered an online competition, which was more like a virtual training programme.
It put the candidates through some rigorous testing and the top 10 athletes were invited to train with the team at its base in Spain.
From there, the squad was cut to three. Remarkably another New Zealand rider in Wellington's Ione Johnson made the final three.
But with just one spot available, it was Harris who emerged victorious.
She learned the news on Saturday and told Cycling Weekly it was unexpected and thrilling.
''I can't believe I did it,'' she said.
''I'm so happy. I entered hoping, and wanting, to win but when I heard my name called out, it was a feeling of complete shock.''
Harris, who won the women's under-23 72km road race at the nationals in Cambridge last year, will join Wanaka's Mikayla Harvey as the second New Zealander to be debuting in the women's world tour ranks next year.
Harris' next assignment is the New Zealand elite national championships in Napier next month. She will join her new team after that.
