To clarify the effect of stoichiometric of soil available nitrogen (N) and phosphorus (P) on the photosynthetic characteristic of wheat, we conducted a pot experiment with 16 different NP levels to examine the characteristic of photosynthetic gas exchange and fluorescence parameters of ‘Zhenmai168’ in response to different NP treatments. Our results showed that: (1) The chlorophyll content of the wheat leaves increased with an increase of soil available N and P. (2) Photosynthesis (P_n) exhibited a continuously increasing trend with decline of soil N/P ratio under the condition that soil available N was less than 258.4 mg·kg^-1. In contrast, photosynthesis (P_n) firstly showed an increasing trend and then decreased under higher N level with 308.4 mg·kg^-1. (3) F₀, F_m, qP and Φ_PSⅡ values of wheat increased 7.27%-20.00%, 5.28%-16.15%, 6.64%-20.92% and 6.95%-18.82%, respectively, and NPQ value decreased 7.42%-25.63% under decline of soil N/P treatments with the same level of available N. Our results suggested that both of P_n and Φ_PSⅡ of Zhenmai168 reached the highest level and showed strong light energy use efficiency under higher NP level condition with 2.88 value of N∶P ratio.