Chen Guangcheng accused officials in Shandong province of forcing 7,000 women into abortions or sterilisations.
Chinese Human Rights Defenders said he was released from jail in the city of Linyi, where he had helped people sue over the injustices.
Mr Chen, 39, is a contender for this year’s Nobel Peace Prize.
Mr Chen, who lost his sight in childhood, has no formal legal training as the blind were not permitted to attend college.
He has also advised farmers in land disputes and campaigned for improved treatment of the disabled.