The Philippines-based platform had more than 114,000 users, and is reported to have made around ¥650m profit for suspects involved.
An investigation began in 2016 after a tip-off, which saw two website technicians arrested in Shanghai in 2017.
Police then gained access to backend data and were able to target the rest of the group.
Fifty suspects in the online gambling case were arrested in Shanghai, Fujian, Zhejiang and Guangdong, Xinhua said, while another six returned to China from the Philippines and handed themselves in.
As like most of Southeast Asia, gambling is illegal in China, with the exception of the two state-run lotteries and the island of Macau.
This comes after Chinese authorities suppressed an illegal online gambling ring during the World Cup in Guangdong Province, where six people were arrested and bank accounts worth almost $750,000 were frozen.
