A broadband YIG tuned oscillator (YTO) frequency sweeping signal generator based on the DDS-PLL method is introduced. A linear sweep frequency sinusoidal signal generated by DDS is used to a reference signal of the YTO PLL (Phase-Locked Loop), and the other input of PLL is the linear frequency sweep signal of the YTO, the resulting error correction signal drives the YTO FM coil. Error correction signal can compensate the YTO nonlinear error, thereby ensuring that the YTO sweep signal generator output is accurate, linear frequency sweep signal. The signal generator module has been successfully applied to a spectrum analyzer.