The invention discloses a wavelet analysis-based grinding machining working condition detection system and a wavelet analysis-based grinding machining working condition detection method. The system comprises a sensor information acquisition module, a corresponding table module for working conditions and acoustic emission frequency band power, and an intelligent working condition judgment and output module. An acoustic emission sensor is arranged on a grinding machine and transmits acoustic emission signals to the corresponding table module for the working conditions and the acoustic emission frequency band power and the intelligent working condition judgment and output module respectively; the corresponding table module for the working conditions and the acoustic emission frequency band power acquires the standard power intensity of each frequency band by using a wavelet transformation analysis method, and constructs a corresponding table between standard working conditions and standard acoustic emission frequency band power intensity Pst; and the intelligent working condition judgment and output module performs wavelet transformation analysis on the acoustic emission signals to acquire current power intensity, matches the current power intensity with the Pst, calculates a fit error value and determines and outputs a current grinding working condition.