Method for measuring micro-water content

The invention discloses a method for measuring micro-water content. The method comprises the following steps of 1, respectively mounting a water absorption pad and a lens on a hollow lens fixing support; 2, enabling a laser to emit the laser light, and reflecting the laser light on the front face and the rear face, making contact with the air medium, of the lens respectively; 3, transmitting the reflected light along a reverse path which is completely opposite to the incident light or forms a certain included angle with the incident light; 4, forming two columns of light waves with the same frequency; 5, enabling the two columns of light waves with the same frequency to meet in the air and superposing to form the bright and dark stripes; 6, using a photoelectric converter to generate an interference wave crest; and 7, using a signal processing system to judge the micro-water content in a detected gas according to the phenomenon that the center of the generated interference wave crest moves. According to the m