State‐of‐the‐art triboelectric nanogenerators (TENGs) typically employ fluoropolymers, highly negative chargeable materials in triboelectric series. However, many researchers nowadays are concerned about environmental pollution caused by poly‐and per‐fluoroalkyl substances (PFAS) due to their critical immunotoxicity as fluoropolymers are likely to release PFAS into the ecosystem during their life cycle. Herein, a sulfur‐rich polymer (SRP)/MXene composite, offering high‐performance yet sustainable TENG is developed. Value‐addition of sulfur into SRP‐based TENG has huge advantages since sulfur is abundant waste from petroleum refining and possesses the highest electron affinity (−200 kJ mol−1) among polymerizable atoms. MXene segregated structure is introduced into SRP to achieve homogeneous distribution without electrical percolation by utilizing below 0.5 wt% of MXene, resulting in a significantly enhanced dielectric constant without a drastic increase of dielectric loss. Due to homogeneous MXene distribution, SRP/MXene composite‐based TENG demonstrates 2.9 times and 19.5 times enhances peak voltage and peak current compared to previous SRP‐based TENGs. Additionally, it exhibits reusability without critical reduction of modulus and TENG performance due to dynamically exchangeable disulfide bonds. Finally, after the corona discharging and scaling‐up process to a 4‐inch wafer size, SRP/MXene composite‐based TENG exhibits an 8.4 times improvement in peak power density, reaching 3.80 W m−2 compared to previous SRP‐based TENGs.