Abstract: It is difficult to apply traditional three-stage current protection to active distribution networks. This problem is addressed first by analyzing the magnitude and phase characteristic differences of the positive sequence current fault components（PSCFCs） when faults occur inside and outside distribution network protected feeders with different distributed generator types. A new method of current longitudinal differential protection based on adaptive braking compensation coefficient is proposed. The method uses the modified e-exponential function to construct the braking compensation coefficient. From the phase difference and amplitude ratio of PSCFC on both sides of the line, the compensation degree of the braking current is adaptively determined. To effectively cope with the negative impact of unmeasurable load branches on protection reliability, an additional criterion is constructed using the action equation of amplitude-comparison directional impedance relay. The simulation results show that compared with the traditional current longitudinal differential protection, this method can meet active distribution network protection needs in various fault scenarios with high sensitivity, reliability, ability to withstand transition resistance and resistance to time synchronization errors.