Active noise reduction back cushion capable of being freely bent

The invention belongs to the technical field of passenger cars and railway vehicles, and provides an active noise reduction back cushion capable of being freely bent, a passenger car seat with the active noise reduction back cushion capable of being freely bent and a railway vehicle cab for active noise reduction by adopting the mode. The passenger car seat and the railway vehicle cab comprise a seat, a freely bendable back cushion and an active noise reduction system. According to the back cushion capable of being freely bent, aluminum alloy is adopted to serve as a headrest supporting frame, so that the back cushion has certain supporting strength and free bending performance at the same time, memory foam is used for filling and wrapping, and the riding comfort of a driver and passengers is guaranteed. The active noise reduction system comprises a reference sensor, a comparison sensor, a sound wave generator and a signal controller, and the signal controller receives an environment noise signal and a feedba