The performance of organic-inorganic hybrid thermoelectric thin films can be dramatically enhanced by optimizing energy filtering and carrier transport states at the organic-inorganic interfaces. In this work, p-type "Sb2Te3/CH3NH3I/Sb2Te3" multilayer thin films were firstly fabricated with varied contents of CH3NH3I, and then an annealing process was used in order to form homogeneous organic-inorganic hybrid thin films. The results revealed that the introduced organic component can promote thin film growth and develop a dense nanostructure with improved crystallinity, thus resulting in a significantly increased Seebeck coefficient and a reduced thermal conductivity as a result of the optimized electronic transport characteristics and enhanced effects of phonon scattering. As is expected, the thermoelectric performance of the hybrid-nanocomposite films is enhanced, achieving the maximum ZT value of 1.55 at a temperature of 413 K, which is several times higher than that of the as-fabricated film, thereby suggesting that the proposed strategy can be applied as an efficient method for the preparation of high-performance thermoelectric thin films.