The invention belongs to the technical field of sensor manufacturing, in particular to a piezoelectric flexible sensing device. The piezoelectric flexible sensing device mainly consists of a piezoelectric flexible sensor, an electromyographic signal preprocessing module, a Bluetooth wireless transmission module, a Bluetooth wireless receiving module, an electromyographic signal analysis processingmodule, a prosthesis motion control module and the like. The piezoelectric flexible sensor collects muscular tension signals and transmits the signals to the electromyographic signal preprocessing module, the electromyographic signal preprocessing module transmits preprocessed electromyographic signals to the electromyographic signal analysis processing module, and the prosthesis motion control module controls the motions of prostheses according to the electromyographic signals processed by the electromyographic signal analysis processing module. The device is reasonable in structure, scientific and reliable in principle, great in product stability, high in sensitivity and capable of greatly improving the life of the disable. By adopting built-in sensors, epidermal tissue can be avoided to directly apply the electromyographic signals, the signals can be more effectively and accurately collected to help manipulation of the prostheses, and therefore the movement functions of the prostheses can be more equivalent to those of original limbs.