A load sharing method includes: establishing a first tunnel and a second tunnel between a first network device and a second network device, where the first tunnel and the second tunnel form a bonding tunnel through hybrid bonding; sending, by the first network device, a plurality of data packets to the second network device; determining, by the first network device, a usage status of buffer space of a bonding tunnel reorder buffer of the second network device based on an acknowledgment response returned by the second network device; and performing, based on the usage status and according to a specified load sharing policy, load sharing between the first tunnel and the second tunnel for a packet to be transmitted by the first network device to the second network device.