Abstract: Aiming at the generation of true random numbers, a true random number extraction method based on light scintillation images in atmospheric turbulence was proposed. First, we used a camera to obtain the light spot images of the laser with a wavelength of 532 nm propagating through atmospheric turbulence. Then, according to its scintillation characteristic, we selected the light spot images by fixed-interval selection and multiple-step selection, respectively, the fixed interval was selected as 50 frames, the multiple steps were selected as 30 frames, 70 frames and 100 frames. The correlation of the obtained light spot images was weak, and the correlation coefficient was less than 0.3. Because of the influence of the turbulence effect, the pixels in the image changed irregularly. We calculated the combination of pixels to extract the random sequences. Finally, we tested the extracted random sequences by the national institute of science and technology(NIST) randomness test method. Experimental results show that the random effect of random sequence with the fixed-interval selection is general and the test results have the P value less than 0.01, while the P value obtained by multiple-step selection are all greater than 0.01 and the random sequence can pass the randomness test.