There are many detection technologies for watermelon quality nondestructive examination, which includes acoustic property, vibration frequency spectrum, electric inductivity, visible and near-infrared spectroscopy, nuclear magnetic resonance, et al, but there is not a detection device used in market. According to the present detection methods, proposes that by sound detecting methods, uses LABVIEW collecting technology to develop desk-top watermelon nondestructive detection devices and DSP processing technology to develop the portable type.