China bear Peter Navarro is telling investors not to put their money in the country because its economic model is unsustainable.

"What you got is a mercantilist export-driven model for China coupled with a Keynesian-on-steroids stimulus that occurs at the municipal level by building all sorts of public infrastructure that requires stealing land from farmers," the University of California, Irvine economics professor told CNBC's "Power Lunch" on Wednesday.

Navarro, who co-wrote "Death By China," attributes China's slowing growth to less demand coming from the U.S. and Europe for Chinese exports.

"The problem is simply that Europe and the U.S., which provided the 10 percent growth year after year for three decades, are now too weak to sustain that," he said.

In addition, China is facing rising wages, labor issues, water shortages and a stock market and real estate bubble, Navarro said.

Read MoreAsian stocks mixed in choppy trade after China GDP

On Wednesday, China's statistics bureau announced that GDP grew an annual 7 percent in the first quarter, slowing from 7.3 percent in the previous quarter. That was the country's slowest pace of growth in six years, suggesting the world's second-largest economy was still losing momentum.

—Reuters contributed to this report.