The invention discloses a wireless stress tester of a hydro-power generating unit. The wireless stress tester at least comprises a lower distributed acquisition system (2) for signal acquisition, processing and storage and upper and lower wireless signal transmitters (10, 5) for signal transmission; the lower distributed acquisition system (2) comprises a signal conditioner (6), a lower main controller (7) and a precision power supply (9), wherein the signal conditioner (6) is used for voltage and current conversion, photoelectric isolation, electrostatic shielding and multistage amplification, and the lower main controller (7) is used for processing the output signals of the signal conditioner (6) and used for A/D conversion, data storage and wireless signal transmission; and the lower distributed acquisition system is in wireless data communication connection with a receiver of the upper wireless signal transmitter (5) in an upper main controller (4) through a transmitter of the lower wireless signal transmitter (10). The wireless stress tester has the advantages of high precision, acquired number accuracy, high time efficiency, reasonability and accuracy of the acquired test data, improvement on the success rate of test, and capability of ensuring the fairness of the test result.