An uplink data transmission method includes a report procedure. The report procedure includes: obtaining a start page number according to a page queue header of a page queue, where the page queue has a plurality of page records in sequence, the start page number corresponds to one of the page records, each of the page records includes a page size, and the page size is a sum of data sizes of packets corresponding to the page record; summing the page size of the page record corresponding to the start page number and the page size of each of the subsequent page records one by one to calculate a first sum result; and outputting the first sum result as a report size.