To address protection issues arising from distributed generation integration, current differential protection has been increasingly applied in active distribution networks. In distribution feeder sections, T-connected load branches, such as transformers or induction motors, are commonly present. The non-fault transient currents generated by these branches may lead to the maloperation of current differential protection. Focusing on this problem, this paper analyzes multiple scenarios where T-connected transient currents may cause differential protection maloperation. Based on the characteristics of transient current waveforms, a blocking scheme based on the attenuation characteristics of the positive-sequence component of the differential current is proposed. This scheme employs the Fourier algorithm to extract the fundamental current amplitude and distinguishes fault differential currents from non-fault transient differential currents according to the attenuation rate of the positive-sequence current amplitude. Simulation results and field data verification demonstrate that the proposed scheme can effectively avoid the risk of protection maloperation caused by T-connected transformers or induction motors without compromising the sensitivity of current differential protection.