The stratified altitude which is suitable for four seasons is further identified

The gain of the isoplanatic angle of the multiconjugte system is deduced compared to classical adaptive optics system. Based on the deduction, the maximum gain conjugate position of level and upright-propagation is analysised. For the first time, the upright-progagation analysis had been combined with Hefei China´s domestic air refractive index structure constants, which are different in four seasons. In each layer of the different seasons, the best conjugate position is calculated. The conjugate height difference between the maximum gain of the isoplanatic angle in the four seasons is also analysised. The stratified altitude which is suitable in four seasons is further identifyied, providing Hefei with a reference for setting up dualconjugate adaptive optics system.