You need to transit in Beijing, please check the flights carefully about the layover. if he will stay in Beijing airport for not more than 24 hours, then he does not need a transit visa. otherwise, he needs to apply for a transit visa to China in Macao. The requirements are as follows:
1. Valid your air tickets to Pakistan (original and copy)
2. Original passport with validity more than six months and minimum 2 blank visa pages;
3. Photocopy of the first 2 pages (personal information) of the passport and the recent Chinese visa page if there is any;
4. Fully completed Visa Application Form in Chinese or English, attached with one of the applicant's recent color photograph (30mm X 40mm)