By using easily accessible oligothiophene donors and acceptor, all-oligothiophene organic solar cells (AOT-OSCs) were realized. The devices fabricated with thiazole-centered donor Tz6T and quaterthiophene-based acceptor A4T-16 exhibited a satisfactory power conversion efficiencies (PCEs) of 9.30 %. Moreover, the devices based on Tz6T/A4T-16 binary demonstrated an excellent industrial figure of merit (i-FoM) of up to 0.168 which represented one of the best cost-effectiveness in all small molecule organic solar cells, suggesting the strong potential of all-oligothiophene combinations in developing OSCs with both low cost and high efficiency.