BEIJING, Jan 14 (Reuters) - China's soybean imports hit a record high in 2020, customs data showed on Thursday, after crushers ramped up purchases amid improved margins and healthy demand from the country's rapidly recovering pig sector.

China, the world's top soybean buyer, bought 100.33 million tonnes of the oilseed in 2020, up 13% from 88.51 million tonnes in 2019, according to the General Administration of Customs, the highest annual imports on record.

December's imports came in at 7.524 million tonnes, down 27% from 9.54 million tonnes a year ago and down also from November's 9.59 million tonnes, as shipments slowed after abundant arrivals in earlier months.

China has been rebuilding its pig herd, which was ravaged by the deadly African swine fever disease, with the pig population now approaching normal levels, according to state media.

Demand had been very strong, said a manager with a crusher in northern China, especially in the earlier months of the year.

"Imports in the new year are expected to hit a new record high," he added, declining to be named as he was not authorized to speak to the media.

Crushers bought Brazilian soybeans early in 2020, and turned to U.S. cargoes in the fourth quarter when American beans hit the market, and as Beijing stepped up purchases of U.S. farm produce to meet the terms of a Phase 1 trade deal. (Reporting by Hallie Gu and Dominique Patton Editing by Shri Navaratnam)