"高压输电线路网" can be translated into English as "high-voltage power transmission line network" or "high-voltage transmission grid".
"High-voltage power transmission line network" emphasizes the network composed of high-voltage lines for transmitting electricity.
"High-voltage transmission grid" is a more concise and commonly used term in the electrical engineering field, referring to the interconnected system of high-voltage transmission lines and associated facilities.
Both expressions are accurate and can be used depending on the context and the level of formality required.