Abstract: With the access of a high proportion of highly stochastic photovoltaic (PV), precise location and fast calculation have become two important characteristic indicators for the application of real-time power flow data to quickly and accurately determine the location and capacity reactive power optimization methods in active distribution network compensation capacitors. For distribution networks in agricultural and pastoral areas characterized by light load or containing long lines, both the location accuracy and calculation speed of five different index methods for compensation capacitor siting are investigated in the paper. For IEEE 12 distribution network, 53-bus distribution network and active 37-bus distribution network in agricultural and pastoral regions, the optimal locations for capacitors are determined based on loss reactive power sensitivity index method, loss voltage sensitivity index method, active power loss index method, voltage stability index method and entropy power method. The particle swarm algorithm is employed to optimize the capacity of compensation capacitors. The loss reduction and average deviation of voltage in different models were compared to determine the accuracy of capacitors siting in different methods, and the calculation speed of different methods was compared. The results demonstrate that the active power loss is substantially reduced after the optimization by the five methods. For the location of compensation capacitors, the power loss index method proves to be the most effective one, achieving the highest loss reduction. It is applicable to different active distribution networks. In comparison with the entropy weight method, the power loss index method exhibits superior computational speed, achieving an average calculation efficiency improvement of 65.9%.