Electromagnetic acoustic transducer（EMAT）sensors are widely concerned because they do not need couplers and can be used in high-temperature environments. However, there are problems such as low energy conversion efficiency, small amplitude of ultrasonic echo signal, and easy to be disturbed by noise, which need to be further studied. According to the working mechanism of the EMAT, through analyzing the characteristics of the echo signal of ultrasonic Lamb determines the index of receiving circuit, design and optimize the impedance matching circuit, preamplifier circuit and low-pass filter circuit, and design the digital bandpass filter for further signal processing. Firstly, the preamplifier circuit is simulated to make it capable of receiving small signals. Then a three-stage MFB low pass filter circuit is adopted to eliminate the spatial coupling noise. The EMAT flaw detection test of aluminum plate was made and built by circuit hardware. The results show that the designed receiver circuit can detect lamb wave well, which provides a foundation for the development of the testing system.