The invention discloses a glass defect detection method. The method comprises the following steps: irradiating a glass sample to be detected with a light source to obtain transmitted light; performing fourier transform on phase information, carried by the transmitted light, into displacement information; judging whether the glass sample to be detected has a defect or not according to the displacement information; if the defect exists, detecting a defect position of the defective glass sample to be detected. By adopting the glass defect detection method, a corresponding relationship between an optical path difference and a phase difference is established according to aplanatism among objective images through an optical path theory, the phase information carried by the transmitted light is taken as a medium for thickness information of the glass sample to be detected according to a frequency shifting property in Fourier optics, the phase information is converted into the displacement information and light intensity information which are recorded in a camera, and sample thicknesses corresponding to different grey values are worked out through corresponding solving algorithms according to a corresponding relationship between the thickness of the glass sample to be detected and a image grey value. By adopting the method, the defect of a glass product can be detected rapidly and accurately.