A defect detection system and method enable a fastened crystalline silicon product to generate micro-vibration by a micro-vibration excitation device, so as to enable the crystalline silicon product to generate an excitation signal, then to acquire the excitation signal by a acquisition device, so as to analyze the excitation signal acquired by the acquisition device in the time and frequency domain by an analysis detection device with a specific analysis, and to obtain an analysis result, at last, determine a defect state of the crystalline silicon product according to the analysis result.