The diagnosis on growth situation and health of cabbage that suffer from attack of diamondback moth is important link during the planting process of cabbage.Spectral imaging technology have obvious advantages of acquiring spatial and spectral information,so it has became the research hotspot at home and abroad.The spectral imaging system which consist of LCTF(liquid crystal tunable filter)and monochrome CMOS camera is used to measure reflectance spectrum of cabbage leaves which have suffered from attack of diamondback moth during different stages.Then the changes of characteristic wavebands and spectral parameters are analyzed.The results indicated that:(1)characteristic wavebands of cabbage leaves which have suffered from attack of diamondback moth have the trend of moving towards the direction of blue light wavebands,this phenomenon can provide good indicative function to the research on the degree of attack of diamondback moth.(2)the red light edge moves towards blue light and the red light spectral trough goes up in spectral characteristic parameters.In a word,by using the method which is combined characteristic wavebands with the spectral characteristic parameters in the area of spectral imaging technology has the significant advantages of monitoring the cabbage leaves on attack of diamondback moth.