In order to clarify the effects of submergence stress on rice growth during jointing stage, flood stress status was simulated through rice flooding test by designing different stress levels with flood depth and flood duration and analysis of leaf area, net photosynthetic rate and dry matter change at 1st,3rd and 7th day after drainage and the whole growth period of rice. The results showed that the flood treatment of rice plant continued after drainage, and rice leaf area index(LAI) gradually decreased, and Pn rises first and then gradually decreases. Meanwhile, the dry matter accumulation shows a trend of decrease first and then increase. Both LAI and Pn of the flooded rice were lower than the CK treatment, and the rice LAI showed 3/3h<2/3h<1/3h, long time total submerged treatment of rice LAI was only 69.53%~70.29% of CK treatment. The total flooding treatment occurred at the end of the reproductive period with Pn was greater than 1/3h and 2/3h, and the quality of dry matter was basically unchanged. Our results can provide the basis for the safe production of rice.