Abstract: In this paper, we propose a distributed photovoltaic participation strategy for voltage optimization control of medium voltage distribution networks, addressing the voltage off-limit issues in distribution networks with distributed photovoltaics and the incomplete measurement scenarios of distribution networks. A voltage optimization control model is constructed to minimize transmission losses in a distribution network with distributed photovoltaic. The study proceeds with a distributed solution algorithm that utilizes limited communication and information exchange among neighboring nodes. By leveraging the measurement information from nodes hosting distributed photovoltaic and key positions, as well as facilitating the communication between adjacent nodes, an improved dynamic projected primal-dual distributed algorithm is proposed to solve the optimization control model. The convergence of the algorithm for convex optimization problems is mathematically analyzed and proven. Subsequently, a set of voltage control strategies for the substation coordinated with distributed photovoltaics is proposed, taking the possibility of insufficient reactive power capacity in distributed photovoltaics into account. Finally, the effectiveness of the proposed algorithm is demonstrated using the IEEE 33-test system as an example. The results demonstrate that the algorithm is capable of effectively solving voltage violation issues in distribution networks and it significantly reduces transmission losses to a level comparable with the optimal solution.