Wavelength as an important parameter of lasers, in military applications and medical applications need to measure wavelength, traditional wavelength measurement devices are not only expensive, but also cumbersome to operate. A wavelength measurement method based on dual-elastic optical modulation technology is proposed to realize rapid measurement of wavelength, and one data point can be measured every 200ms. The laser under test is loaded into the optical carrier signal by the bullet light modulator and the λ/4 standard waveplate with calibrated optical path difference, and the phase delay of the laser passing through the standard waveplate can be obtained by analyzing the optical signal, and the wavelength information of the corresponding laser can be further solved. The experimental results show that the relative error of the wavelength of the 632.8nm laser is 0.1%, the standard deviation is 0.11nm, the accuracy is 99.9%, and the measurement of 532nm and 650nm wavelength lasers is also more accurate, indicating the universality of the method.