The speed measurement of a high-speed micromotor often requires speed sensors, increasing the complexity and cost of the system. To solve this problem, a high-speed micromotor measurement method without a position sensor is proposed in this paper. A current probe is used to obtain the current signal of the high-speed micromotor. The collected signal is processed by adaptive wavelet filtering for noise reduction, and zero-crossing detection is used to calculate the frequency of the signal after noise reduction, so as to calculate the motor speed in real time. A photoelectric optical fiber sensor is used to verify the accuracy of motor speed measurement results. The results show that the difference between the speed measured by proposed method and the speed measured by the photoelectric optical fiber sensor is only 0.4%. This method is expected to be widely applied in the fields of motor performance detection and motor fault diagnosis.