The optimization of thermoelectric (TE) properties in TE materials requires controlling intrinsic factors such as order/disorder in crystal and chemical structures. Although heterogeneous interfaces play a key role in regulating TE properties, the corresponding atomic disorder-order has been ignored in composited systems. We demonstrate examples of GeTe/SnTe compositing for tuning CuInTe2 TE properties. Evidences of increased short-range order and nanoclusters with local chemical order are presented via synchrotron X-ray pair distribution function and scanning transmission electron microscopy. Specifically, GeTe/SnTe compositing within CuInTe2 enhances short-range order. Nanodomains of CuInTe2(GeTe)x are accompanied by a significant atomic-intensity fluctuation that intensifies the scattering of phonons. In contrast to CuInTe2(GeTe)x, nanoclusters with local chemical order are observed in CuInTe2(SnTe)y, accompanied by a weak atomic-intensity fluctuation, which provides superior carrier transport channels and power factor for CuInTe2(SnTe)0.01. Ultimately, a maximum thermoelectric figure of merit zT of ∼1.0 is reported for CuInTe2(SnTe)0.01, which is 54% greater than that of pristine CuInTe2, and higher than the 0.86 for CuInTe2(GeTe)0.01. This work demonstrates new disorder-order insights that reveal the mysterious roles of compositing for tuning TE transport.