With the increasing of the wind power penetration, the network loss and voltage fluctuation of the wind farm is becoming more and more serious. In this paper, the cable selection based on the location of Doubly Fed Induction Generator (DFIG) is studied, and the DFIG's reactive power limit is analyzed. DFIG is commonly utilized to supply reactive power for power grid, thus, the reactive power of DFIG, the number of fixed reactive compensation device, the reactive power output of Static Var Compensator (SVC) and the onload tap changing transformer tap are taken as the control variables. Then, the minimum objective function is established as the sum of total voltage deviation and active power loss of wind farm. The discrete variable is analyzed by employing the Linear decreasing Weight Particle Swarm Optimization (LinWPSO), and the optimal solution of reactive power optimization is successfully obtained. Finally, a case study is included for verification. It is shown that the decentralized and coordinated control of DFIG which considering cable selection can effectively reduce network losses and voltage fluctuations.