The invention discloses a method for improving a signal-to-noise ratio of femtosecond laser by using chirp matched optical parametric chirped pulse amplification and a device thereof, which belong to the technical field of ultra-short pulses. The method comprises the following steps of: firstly, stretching the femtosecond laser with a signal-to-noise ratio to be improved output by a femtosecond laser light source into chirp signal light; secondly, performing high magnification on a signal and performing low magnification on a noise by using the chirp matched optical parametric chirped pulse amplification so as to improve the signal-to-noise ratio of the chirp signal light; and finally, compressing the chirp signal light into femtosecond laser with a high signal-to-noise ratio by using an optical pulse compressor. The device for implementing the method comprises a femtosecond laser light source, a femtosecond laser, a first non-linear optical crystal, a second non-linear optical crystal, a first light pulse stretcher, a second light pulse stretcher, an optical pulse amplifier, an optical pulse compressor, a first dichroic mirror and a second dichroic mirror. The method and the device of the invention can not only improve the signal-to-noise ratio of the femtosecond laser effectively, but also realize high-efficient amplification of the femtosecond laser.