This application discloses a data fusion method and a related device. The method includes: obtaining vehicle sensing data, where the vehicle sensing data is obtained by a vehicle sensing apparatus by sensing a road environment in a sensing range by using a vehicle sensor; obtaining roadside sensing data, where the roadside sensing data is obtained by a roadside sensing apparatus by sensing a road environment in a sensing range by using a roadside sensor; and fusing the vehicle sensing data and the roadside sensing data by using a fusion formula, to obtain a first fusion result. According to the foregoing solution, overlapping can be implemented between the sensing range of the roadside sensing apparatus and the sensing range of the vehicle sensing apparatus can be implemented, so that the sensing range is effectively extended.