Sun Dawu, an outspoken rural businessman who has been a thorn in the side of China’s ruling Communist Party, has been formally arrested on a number of charges, months after being taken into detention.

Mr. Sun, who has been held in the northern province of Hebei since November, faces charges of illegal fund-raising and obstructing public service, among other offenses. He was formally arrested on Wednesday, according to an arrest notice provided on Saturday by one of his lawyers.

The arrest of Mr. Sun — a vocal critic of the Communist Party’s top leader, Xi Jinping, and his crackdown on civil society — comes amid broader efforts by Mr. Xi to muzzle business leaders and bring China’s private sector to heel.

Beijing has punished a number of high-profile tycoons recently. Ren Zhiqiang, a retired real-estate mogul who had called Mr. Xi a clown, was given an 18-year prison sentence last year. After Jack Ma, China’s most famous business leader, criticized Chinese regulators in October, his e-commerce empire Alibaba and fintech giant Ant Group became targets, and Mr. Ma has since kept an uncharacteristically low profile.

The authorities have said little about Mr. Sun’s alleged offenses. He and 24 other people were detained in November amid a land dispute between his company and a state-owned farm. At the time, the police said only that Mr. Sun, 66, and others were being held on suspicion of “provocation, disrupting production and operation and other illegal crimes,” according to a police notice.

The fates of the other people detained are not known. The authorities in Gaobeidian, the city in Hebei where Mr. Sun is being held in a detention center, did not respond to a request for comment.

Mr. Sun, a veteran of the People’s Liberation Army, worked at China’s state-owned Agricultural Bank of China before starting his own business, called Dawu Agricultural and Animal Husbandry Group, which now employs thousands of people.

He built a town in Hebei called Dawu City, complete with services like a 1,000-bed hospital, and cultivated the image of a benevolent corporate leader. His sayings, such as “I’d be honored if my hospital loses money,” were posted around his company’s campus.

Mr. Sun also provided venues for conferences held by liberal and reform-minded groups. He maintained friendships with dissidents long after they became politically toxic. When human rights lawyers were arrested, he offered to pay for their defense.

Mr. Sun had been arrested before, in 2003, after defying the government. Then, a group of lawyers, academics and journalists successfully campaigned for his release. But under Mr. Xi’s rule, criticism of China’s leadership and support for liberal causes carries higher stakes, and there has been no such wave of public support this time.

The Nobel Peace laureate and human rights advocate Liu Xiaobo, who died in detention in 2017, once said that Mr. Sun posed a “tremendous challenge for the current system” because he had both courage and the resources to push for change.

“The government,” Mr. Liu wrote, “will definitely go after him with murky laws.”

Cao Li contributed research.