The case is the largest-ever trade conflict between the two sides, involving more than $20 billion in terms of total volume, according to Sun Yongfu, director general of the department of European affairs of the ministry.

"Although Europe has lost its title as the largest destination for Chinese exports, it's still our largest trade partner," Sun said. "Cases like this damage the overall reputation of Europe among the Chinese public."

"This case is huge in terms of value and has the potential to hurt the local industrial chain," Yao said.

Chinese companies said they hope that the government can help to solve the dispute through dialogue.

"Many PV solar panel producers couldn't pay back their loans to banks and went bankrupt because of the investigations from the US and EU," said a general manager at a solar company in Shandong province, who declined to be named.

He said that his company's profits have dropped 80 percent in the last three years and that it will definitely be at loss this year.

Even so, he said the company is doing better than most in China since hundreds of medium- and small-scale solar panel makers have shut down their factories, while his company is still producing, albeit with a very small output.

"Some companies moved their factories to Taiwan or to foreign countries such as Indonesia and Thailand to avoid the ruling, but I don't want to," he said. "I'm counting on the Chinese government to solve this with the EU."

China's trade with the European Union decreased 1.9 percent year-on-year to $124.41 billion in the first quarter, the General Administration of Customs said on Wednesday.

Wei Tian contributed to this story.