Fang Zhongyue was detained in Suzhou city after a patrolman noticed him acting suspicious at around 1 am near a textile factory in Wujiang District.
He was taken to the local public security bureau for questioning where Fang confessed that he had murdered his fellow crew members, state-run Xinhua news agency reported.
Five men were found dead early Thursday morning aboard a fishing vessel in waters off Zhoushan City in Zhejiang Province.
Fang, however, was missing, along with a life raft, prompting authorities to announce a USD 8,000 reward for information leading to his arrest, according to Putuo District Police.