Enhanced photovoltaic characteristics of bulk heterojunction organic solar cells based on blends of poly [9, 9'-dioctyl-fluorene-co-bithiophne] (F8T2) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6) C61 were achieved through microwave annealing treatment. The absorption and photoluminescence spectra of the active layers with 1:1 ratio in weight were characterized under microwave and common annealing oven. Compared with the oven annealing, the absorption spectra of active layer were enhanced in intensity as well as the wavelength range of absorption little broadened after microwave annealing; the intensities of PL spectra of the blends were also further quenched compared with that of pristine F8T2. The highest power conversation efficiency of 1.18% was achieved by microwave annealing for 90 s compared with 0.86% using annealing oven. The enhanced performance of cells is attributed to the improved morphology and modified charge transport pathways through microwave annealing.