【目的】 伴随成本快速下降，分布式光伏在保障性收购政策下近年来实现了快速发展，加剧了配电网运行压力并带来新的消纳问题，亟需设计高效、可执行的市场化机制引导光伏产业健康发展，为此，设计了适应配电网市场的分布式能源两阶段交易新机制。 【方法】 首先基于日前预平衡确定配电网基准运行状态，根据线路阻塞、电压越限等情况判断是否触发分布式交易启动条件；然后再按需开展分布式能源交易，通过价格信号调动源荷储多环节资源优化配电网运行。为激励市场主体交易行为对系统运行的支撑作用，按照“谁服务、谁获利”的公平原则，提出了价值贡献度评估方法，引入灵敏度因子以分别衡量各市场主体在提高电压质量与缓解线路阻塞两方面的贡献。市场主体的贡献度可以作为分配延缓配电网投资激励费用的依据，提升其参与分布式能源交易市场的意愿。 【结果】 改进的IEEE 33节点系统算例表明，在预平衡阶段出现午间光伏大发导致反向潮流过载和晚间负荷高峰导致低压越限等问题，开启市场后越限风险均已消除，验证了所提机制的可行性和有效性。光伏弃电量下降64%，提升了消纳率，随着可调节资源减少，系统运行改善程度减小，弃光量增多。 【结论】 该机制解决了分布式光伏难以感知市场信号的实际问题，同时能够延缓配电网投资，提高存量设备的利用率，为输配电定价提供了新的思路。

[Objective] Distributed photovoltaics （PV） has developed rapidly in recent years under the guaranteed purchase policy due to the decline in costs. However，unordered growth has increased distribution network operational pressure and created new issues. Thus，an efficient，enforceable market-oriented mechanism is urgently needed to guide healthy PV industry development，coordinate flexible resources，and promote local consumption of new energy. To reduce operational and management burdens on market organizers and participants，this paper proposes a new event-driven two-stage distributed energy trading mechanism for distribution network markets. [Methods] First，the baseline operation state of the distribution network is determined via day-ahead pre-balancing，and whether to trigger distributed trading is judged based on line congestion，voltage over-limit，etc. Then，distributed trading is conducted on demand，using price signal to mobilize resources in generation，load，and storage links for optimal distribution network operation. To incentivize market entities to support system operation through trading，a value contribution evaluation method is proposed based on the "who serves，who profits" principle. Sensitivity factors measure each entity’s contributions to improving voltage quality and alleviating line congestion. Market entities' contributions can serve as the basis for allocating incentives for delaying distribution network investments，boosting their willingness to participate. [Results] Case analysis using the modified IEEE33-bus system verifies the mechanism’s feasibility and effectiveness： in the pre-balancing stage，midday PV over-generation caused branch reverse power overload，and evening peak load led to low voltage violations. after market activation，all violations were eliminated. PV curtailment decreased by 64%，improving consumption rate. With fewer adjustable resources，system improvements diminished and curtailment increased. [Conclusions] This mechanism addresses the practical issue of distributed PVs failing to perceive market signals，while deferring distribution network investments，enhancing utilization of existing equipment，and providing new ideas for future transmission and distribution pricing.