The invention discloses a precise laser wavelength measurement method, which belongs to the technical field of optical precise measurement. A Fresnel zone plate (FZP) with a large numerical aperture is used, a vectorial angular spectrum theory is adopted to calculate a corresponding axial intensity point spreading function when linearly polarized light with an illumination wavelength to be lambdaivertically illuminates on the FZP, a focal length zp is obtained according to a peak value, the lambdai is changed for recalculation to obtain a focal length zp, a linear correlation coefficient is used to evaluate correlation of (lambdai, zp), a linear interval is intercepted, a linear least square fitting method is used to obtain a linear measurement curve, the FZP is used to directly focus a to-be-measured laser beam, a point detector is scanned in an axial stepping mode through a piezoelectric ceramic nano displacement table, the distribution of the axial intensity point spreading function is measured, a centroid method is used to obtain an actual focal length, and the linear measurement curve is used to solve the laser wavelength. The method is simple, the cost is low, the wavelengthmeasurement application range is wide, and the method is applicable to low-cost precise laser wavelength measurement.