提出了一种自适应零相位IIR数字低通滤波器的实现方法，适用于谱图信号的平滑处理。它根据信号的统计特性自动调整滤波器的截止频率，采用倒序方法实现零相位特性，能在较小的信号失真下提高信号的信噪比。对照试验表明，在谱图信号平滑处理中，该滤波器优于常用的移动平均数字滤波器。 An adaptive zero-phase IIR digital low-pass filter implementation method is proposed, which is suitable for the smoothing of spectral signals. It automatically adjusts the cut-off frequency of the filter according to the statistical characteristics of the signal, adopts the reverse order method to realize the zero-phase characteristic, and can improve the signal-to-noise ratio of the signal with smaller signal distortion. Control experiments show that this filter outperforms the commonly used moving average digital filter in spectral signal smoothing.