[Objective] In practical engineering, some asynchronous motors are not equipped with speed sensor and torque measuring instrument, making it difficult to evaluate the energy efficiency of motors, so it is of great significance to study the identification method of speed and torque. This paper proposes an on-line identification method of asynchronous motor operation parameters based on measurable voltage and current. The method has no limitation on voltage and current waveforms, and does not need motor parameters such as stator resistance and reactance, so it is widely applicable and highly practical. [Methods] Firstly, the corresponding rotor slot harmonic frequency was found by fast Fourier transform analysis of stator current, and then the rotor speed was calculated. By constraining the rotor slot harmonic frequency within a certain range through the slip rate, the problem of tooth harmonic aliasing was resolved, enhancing the accuracy of speed identification. Secondly, the stator resistance was calculated by the motor nameplate parameters, and the electromagnetic torque and output torque were calculated by combining the collected voltage and current data. Finally, to further enhance the applicability of the proposed method, the fundamental wave compensation method was introduced to globally scale the filtered signal, accurately restoring the fundamental wave amplitude and further improving identification accuracy. [Results] The direct start and variable frequency drive models of asynchronous motor were built by Matlab to collect output data. Furthermore, experiments were conducted on the Y100L1-4 asynchronous motor to collect voltage and current experimental waveforms. Simulation and experimental results demonstrated that the identification errors for rotor speed and output torque remained within 2% under various operating conditions, thereby validating the feasibility and accuracy of the proposed method. [Conclusion] The proposed method achieves on-line identification of asynchronous motor operation parameters based on measurable electrical quantities, providing a significant reference for real-time identification of asynchronous motor operation parameters in practical engineering applications.