A differential, a power transmission system, and a vehicle are provided. The differential includes: a first planetary carrier, a first gear ring, and a first planetary gear disposed on the first planetary carrier and meshed with the first gear ring; and a second planetary carrier, a second gear ring, and a second planetary gear disposed on the second planetary carrier and meshed with the second gear ring and the first planetary gear, in which the first gear ring and the second gear ring are configured as two power output ends of the differential, the first planetary carrier and the second planetary carrier are configured as power input ends of the differential, and a revolution radius of the first planetary gear is different from a revolution radius of the second planetary gear.