Rolling contact fatigue between the rail tread and the wheel can cause a large amount of surface flaws, and therefore can cause serious damage to the rail operation safety.The traditi onal nondestructive testing (NDT) is not suitable for the rail developing needs and we need to develop a new met hod.The laser-electro magnetic acoustic (EMA) testing system of rail tread is designed based on the pr inciples of the laser-EMA ultrasonic technology and the characteristics of the rail tread flaws.The comparison experiment is conducted by using the piezoelectric transition (PZT) and laser-EMA technology to test t he transverse crack in the rail tread.The results show that the method can preci sely test and locate the crack.From the laser-EMA signal proce ssed based on wavelet threshold denoising,it could be seen that the signal-to-noise ratio (SNR) is greatl y improved and all characteristics of the original signal are remained,which wi ll be convenient for the damage identification and feature extraction. We analyze the influence of left-off effect on the laser-EMA signal,and obtain the relation between the lift-off reffect of EMAT and signal amplitude.Experimenta l results show that this method is feasible and doens′t need coupling medium or good surface condit ions, and could realize non-contact,rapid scanning and precise testing to the rail t read.