Through all solution-processed methods, wearable strain sensors with high gauge factor are demonstrated using thin film of Ag nanocrystals (Ag NCs). Controlling of interval between Ag NCs enables to control a flow of electrons through hopping mechanism and/or tunneling effect, which can enhance gauge factor. In this study, halides ligand treatment is proposed to design interval between nanoparticles to obtain high performances at solid state. Higher sensitivity of ligand treatment with I- is demonstrated by comparisons of experimental results of halides; Br-, Cl-, I-. The origin of the higher performance is discussed with various characterization methods. Careful studies to further enhance the sensitivity is conducted by controlling various conditions in ligand exchange process. These high sensitivity thin film Ag NCs strain gauge sensors allow to measure a delicate movement or signal from various objects. This work provides a low cost and simple method to design high sensitivity wearable sensors for various field such as robotics, or healthcare systems.