The invention provides a wide-band excitation signal generator, and relates to the field of electronic signal devices. A frequency control word is set through a data interface bus, the working frequency of a DDS generator is configured in a CPLD logic control module, variable-frequency sine wave is output through a DA interface after phase accumulation of signals generated by the DDS generator is carried out according to the set frequency control word, sine wave signals enter a conditioning circuit module for conditioning and filtering, and finally, the sine wave signals pass through a power amplifier circuit module, and excitation signals at a preset frequency are output. According to an isolating and conditioning circuit designed in the invention, a first amplifier improves the signal-to-noise ratio and plays a buffer role, an isolating operational amplifier ensures that the output signals are not affected by common-mode voltage and eliminates electromagnetic interference caused by common ground, and a second operational amplifier improves the output ability. In short, the power amplifier circuit improves the reliability of the system, and makes the system work more stably.