Aim at the problem that the energy collection of traditional photovoltaic cells is susceptible to environment and illumination time constraints, a slot Yagi-Uda nanoantenna unit and array was proposed for solar energy harvest. By adopting the finite difference time domain method, the influence of gap spacing on the nano antenna far field directivity and the near field distribution was analyzed. The influence of the absorption characteristics of slot Yagi-Uda nanoantenna array and the different slot spacing on the array antenna absorption rate was studied. The study of far field directivity shows that, when the slot spacing increases to a certain distance, the antenna far-filed pattern appears multi-sidelobe and a new radiation pattern. The analysis of the near field thows that, the new radiation pattern is derived from the high order mode of localized surface plasmon. The simulation results of the antenna array absorption rate show that, in the waveband range from 400nm to 1500nm, with the increase of slot spacing, the absorption rate shows a trend of rising. When the slot spacing is equal to 80nm, the antenna absorption rate is higher in the band range from 400nm to 660nm and the range from760nm to 1300nm, the absorption peak value can reach 98%. The absorption rate exceeds 50% as a benchmark, when the slot spacing is equal to 80nm, the absorption band is widest.