The invention discloses a large-size TFT substrate glass non-destructive micro-waviness detection method. The method comprises steps as follows: a, two guide rails which are in the same direction as aglass conveying roller bed are arranged below the glass conveying roller bed, two vertical moving plates are arranged between the two guide rails at an interval, wherein one moving plate is providedwith a vertical CCD image sensor, and the other moving plate is provided with a light source irradiating downwards and obliquely; b, the bottom surface of a TFT substrate is uniformly frosted; c, thelight source is opened to irradiate the surface of the TFT substrate, and the two moving plates are simultaneously moved along the guide rails to guarantee that the relative positions between the twomoving plates are not changed; the surface of the TFT substrate is scanned by light, the light is continuously reflected to the CCD image sensor, and bright and dark alternated strips are formed on the CCD image sensor; d, the micro-waviness of the TFT substrate glass is judged according to the bright and dark alternated strips. By means of the method, the micro-waviness of the whole TFT substrateglass can be comprehensively detected without damage to glass, and defective products of glass arefavorably and timely found.