The design and principle of a complex modulation and wideband agile signal generator is introduced. Through high capacity FPGA control high speed direct digital frequency synthesizer chip,To generate wideband agile IF signal,Digital FM，PM，AM is also available.Previously produced wideband digital modulation signals, It needs to use wideband quadrature modulator.Because of group delay frequency response and temperature drift of wideband analog quadrature modulator,It’s extremely difficult for precise control of two IF signal phase orthogonality.Emphasis is placed on two direct digital frequency synthesizers,and synchronous processing and real time phase difference control,To produce two agile IF signal with phase orthogonality,They are respective modulated with two quadrature digital baseband signal component,To achieve digital modulation of wideband agile IF signal.On the basis of agile IF signal,Use of the wideband microwave synthesis of local oscillator and direct conversion technology achieve coverage of the whole frequency range.Experiments show that agility bandwidth of the signal generator is 300 MHz,Frequency switching time less than 1 μs,Frequency range is 250 kHz～3 000 MHz,EVM less than 2％ and less affected by temperature,It achieves the various analog modulation,digital modulation,complex pulse modulation,intrapulse modulation and fast frequency hopping, it reduces the complexity,the volume and the cost of the system.