Abstract: It is necessary to detect the fruiter crown diameter for fruiter profile modeling of precision spray. The method of interlaced calculation and the theory of relative crown diameter (RCD) were developed based on the detection mechanism for fruiter crown diameter. The system model about data fusion was established by the relationship between RCD and imaging distance. BP artificial neural network was used for data fusion and the data fusion process was explained. The experimentation results prove that it is feasible to use BP artificial neural network for data fusion between RCD and imaging distance. The influence of imaging distance on detecting RCD was eliminated by data fusion. The maximum fractional error between fusion value and theoretic value is 1.14%.