The invention relates to a differential protection method and device based on wireless communication, and belongs to the field of power system relay protection. According to the invention, after protection devices at the two sides of a protection area are time-synchronized, the two protection devices send current sampling values containing sampling moments collected by the two protection devices in a wireless mode to each other, select a current sampling value at the same sampling moment as the current sampling value at the opposite side after the protection devices receive the current sampling values at the opposite sides, and perform differential protection discrimination according to the current sampling values at the current side and the opposite side; and, if the difference value between the moment when the opposite side current sampling value is received and the sampling moment is larger than a set value, differential protection is not carried out any more. According to the invention, in the protection process, the current sampling values participating in differential protection discrimination are improved, and the current sampling values at the same sampling moment in the current sampling values on the two sides are selected for differential protection, so that the problem of insufficient differential discrimination reliability caused by the inherent defects of long datatransmission delay and large jitter of a wireless communication mode is avoided.