Abstract: Aim To put forward an effective survey technigue of the wavefront distortion caused by the atmospheric turbulence. Methods Supposing the turbu lence concentrates mainly on to two thin layers, one laser beam produces both the sodium guide star and Rayleigh guide star by using the temporal gate. The former can be used to measure the total phase distortion caused by two layers of the turbulence while the latter provides a suitable probe signal for the contribution of the low altitude. A set of equations linking these variables is established and resolved. Results\ The wavefront distortion caused by the high altitude turbulence alone is got. Conclusion The wavefront distortion caused by either low or high altitude turbulence can be obtained easily with this technique, thus the basis is provided for multilayer correction adaptive optics with wide field of view.