To achieve electrical conductivity comparable to metallic materials, electroless deposition has attracted much interest for low-cost fabrication of conductive organic materials in recent years. However, the metallized coatings constructed by such methods usually have to utilize expensive sensitizers and activators, hindering its use in practical applications. Here, a novel method, without the need of sensitizer and activator, was developed for fabricating a flexible and conductive meta-aramid/ polyacrylonitrile (PMIA/PAN) composite film with excellent coating adhesion. We used PMIA as the matrix and introduced PAN components to prepare a series of PMIA/PAN composite films. A strongly bonded conductive CuS coating is obtained by a redox chemical reaction. It was found that PMIA/PAN = 10/1 is the best blending ratio for preparing PMIA/PAN-CuS composite films, and excellent adhesion is exhibited between CuS coating and the pure PMIA/PAN organic substrate even after >15 times tape stripping treatment or 170 min of ultrasonic treatment.