Abstract: In this paper,a TCT（total-cross-tied）PV（photovoltaic）arrays reconstruction method simulating the multi-knapsack model is developed in order to improve the power generation efficiency. The reconstruction method keeps the physical positions of all modules unchanged and only adjusts the electrical connection among them to restrain irradiance mismatch of PV arrays. Aiming at the computational difficulties of the multi-knapsack model in the combinatorial optimization,a TCT PV arrays optimization algorithm based on multi-package model is proposed to simplify computation. The algorithm helps optimizing configuration of parallel groups. The work efficiency increased by 8.32%-10.89%. And a compensation method to PV arrays is designed,which connects extra modules without shaded to the parallel groups with serious occlusion shaded. The compensation contributes much more to improving the power generation efficiency. The work efficiency increased by 22.27%. Finally,both simulation and experiment are taken to prove that the optimization,reconstruction and compensation can effectively improve the power generation efficiency of TCT PV arrays.