Abstract: The large-scale gathering system of the "desert, Gobi and desertification land" is far from the main grid, exhibiting strong reactive power and voltage sensitivity. The wind farm's overall and internal reactive power imbalance generates a large voltage difference on the grid-connected transmission lines and feeders inside the wind farm. Traditional reactive power and voltage control schemes of wind farm are difficult to ensure their safe and economical operation. Therefore, a distributed decision-making refined reactive power and voltage control strategy within the wind farm is proposed. Starting from the physical essence of reactive power demand, a detailed analysis is conducted on the reactive power demand of various components in a wind farm, and specific calculation methods are provided. Then, a distributed multi-center reactive power balance model for wind farm is established, which directly solves the reactive power commands of each reactive power source in the field in a non iterative manner. To measure the unreasonable reactive power flow on the feeder, this article defines the concept of reactive power pass-through and derives its calculation expression. The analysis results of the example show that the distributed decision-making refined reactive power and voltage control strategy within the wind farm can strengthen the local reactive power balance in the wind farm, effectively improve the distribution of feeder voltage, significantly reduce reactive power pass through and active power loss on the feeder, and improve the safety and economy of wind farm grid connection operation.