This application provides a wireless charging device, including: a charging pad and a first controller. The charging pad includes a plurality of charging units, and the first controller is configured to control how the plurality of charging units charge the to-be-charged device. Specifically, the plurality of charging units include a first charging unit and a second charging unit. When a first electromagnetic coupling strength between the first charging unit and the to-be-charged device is greater than or equal to a first threshold, the first controller is configured to control the first charging unit to separately charge the to-be-charged device. When both the second electromagnetic coupling strength between the second charging unit and the to-be-charged device and the first electromagnetic coupling strength are less than a first threshold, and are greater than or equal to a second threshold, the first controller is configured to control the first charging unit and the second charging unit to jointly charge the target to-be-charged device.