A counting method and a communications apparatus are provided. The method includes: determining to retransmit a first protocol layer data packet; and if the retransmission is retransmission for the first time, initializing a retransmission counter associated with the first protocol layer data packet; or if the retransmission is not retransmission for the first time and the first protocol layer data packet is not pending for retransmission, updating the retransmission counter or keeping a value of the retransmission counter unchanged. In this way, RLF can be correctly triggered, to reduce a quantity of times of unnecessary RLF triggering and reduce overheads.