In order to investigate the effect of groundwater depth on maize growth and yield under mulched drip irrigation, selecting the maize of Zhengdan 958 in the case of Shenyang region as test material, five different groundwater depths of 1.0 (D1.0), 1.5 (D1.5), 2.0 (D2.0), 2.5 (D2.5) and 3.0 m (D3.0) were set up by the simulation system. The growth index, photosynthesis, yield and water consumption of maize were analyzed. The results showed that the specific performance of plant height, stem thickness and leaf area index which reached the peak value under different groundwater depths was D1.0 > D1.5 > D2.0 > D3.0 > D2.5. Besides, D1.0 and D1.5 treatments could shorten time after planting when plant height and stem thickness reached the peak by 10~20 days. Compared with other treatments, the net photosynthetic rates and transpiration rates were increased under D1.0 by 18.05%~32.89% and 18.50%~137.24% respectively. Maize yield decreased with the increasing groundwater depths, and the yield of D1.0 was the largest, reaching 17 100 kg/hm². And maize yield increased with the increasing groundwater recharge and water consumption during the whole growth period. Through the path analysis between maize yield factors and yield,it turned out that groundwater depth improved maize yield by increasing leaf area index and grain numbers. In conclusion, groundwater depth of 1.0~2.5 m could shorten the process of maize growth, increase maize yield by increasing the maize leaf area index, then improve the photosynthesis capacity, promote the formation of maize grain in the filling stage,and finally increase grain numbers. These findings could provide scientific guidance for maize planting and water-saving irrigation under different groundwater depths in the middle area of Liaoning Province.