For Fernald forward inversion of airborne lidar signals require an accurate calibrating value, a new calibration method was put forward. Using lidar equation, atmospheric backscattering signal profiles, as well as a known aerosol backscattering coefficient profile, the calibrating values of other signal profiles are determined. Simulation and observation results indicate its feasibility. The aerosol backscattering coefficient profiles inversed by the calibrating value, which is determined by the calibration method, are relatively veracious, and the relative error of aerosol backscattering coefficient caused by the method is less than 20%. It is considered that the calibration method can be applied to Fernald forward inversion of airborne lidar signals.