Abstract: To address the conservativeness of fixed export limits and the voltage violation risk of conventional dynamic operating envelopes under source-load fluctuations, a safety-margin-based dynamic operating envelope method is proposed for low-voltage distributed photovoltaics. Voltage constraints and photovoltaic export limits are first formulated, and voltage sensitivity is used to determine dynamic operating envelopes under different operating conditions. A safety margin coefficient is then introduced to form a more reliable safety operating region. Case studies on a typical low-voltage distribution network show that the proposed method improves photovoltaic export capability while maintaining nodal voltages within allowable limits, providing a practical reference for safety operating region assessment and export boundary determination.