Distributed photovoltaic (PV) entities can be coordinated to provide reactive power for voltage regulation in distribution networks. However, integrating large-scale distributed PV entities into reactive power optimization makes it difficult to balance the individual benefit of each PV entity with the overall economic efficiency of the system. To address this challenge, we propose a market-oriented two-stage reactive power regulation method. At the first stage, a long-term multi-layer reactive power capacity market is created to incentivize each PV entity to provide reactive power capacity, while ensuring their financial interests are guaranteed. At the second stage, a real-time multi-layer reactive power dispatch mechanism is introduced to manage the reactive power generation of distributed PV entities, prioritizing the dispatch of lower-cost PV entities to maximize system-wide economic efficiency. Simulation results based on a real Finnish radial distribution network demonstrate the effectiveness of the proposed method in optimizing reactive power for large-scale distributed PV entities.