本文提出了一种新的二相编码波形－双频级联ＰＮ截断码，并对其信号处理作了详细讨论。理论分析和计算机仿真表明，双频级联ＰＮ截断码缓解了压缩比和多普勒容限之间的矛盾。同时又提出了一种补偿式滤波器抑制距离旁瓣的方法，来进一步扩展多普勒容限和提高主旁瓣比，使该波形达到工程应用的水平。 This paper presents a new two-phase encoding waveform - dual-frequency cascaded PN truncation code, and its signal processing are discussed in detail. Theoretical analysis and computer simulation show that the double-frequency cascaded PN truncation code alleviates the contradiction between compression ratio and Doppler tolerance. At the same time, a compensating filter is proposed to restrain the sidelobe of the distance to further extend the Doppler tolerance and improve the mainlobe ratio, which makes the waveform reach the level of engineering application.