Abstract: With the rapid development of phased array antennas toward large-scale and high integration, a huge number of equal-length cables in their feeding and optical transmission networks have become a key factor affecting system performance, reliability and manufacturing costs. Traditional equal-length cable design methods often rely on manual adjustment or simple topology, with prominent problems such as redundant routing, large volume and weight, and poor manufacturability. Aiming at the core requirements of phased array antennas for low transmission loss and high integration, this paper proposes a multi-level and multi-region optimal design method for equal-length cables by taking a specific product as the research object. Firstly, a simplified geometric model is established according to the array structural characteristics of phased array antennas to facilitate the calculation of cable lengths and routing paths. Secondly, an optimization algorithm is introduced to automatically solve the cable topology and routing network with weighted total length minimization while satisfying the equipment connection constraints. Finally, the effectiveness of the proposed algorithm is verified through three-dimensional routing simulation.