There is a lack of effective decisionmaking indicators in the production of facility vegetables to guide the scientific input of nutrients in China，and the excessive fertilization has become an important bottleneck for the sustainable development of facility agriculture. This paper choosed soil conductivity as the decision index to control nutrient input，and explored the influence of different soil electrical conductivity (EC) on tomato growth，yield and quality to provide a scientific basis for the future production of intelligent facilities. Through the field test of the tomato system in the facility，the visual conductivity sensor was used to monitor the soil in real time，and the integrated water and fertilizer equipment was used for nutrient input. By measuring the tomato growth，yield and quality indicators corresponding to different soil conductivity，the most suitable soil EC for tomato growth was analyzed. The results showed that tomato plant height，stem thickness，leaf SPAD value and other indicators had a quadratic curve relationship with soil EC. By fitting the quadratic curve established at the end of vegetative growth，the plant height reached the maximum at EC 4.03 mS/cm，and the stem thickness and leaf SPAD values reached the maximum at EC 2.93 and 2.54 mS/cm，respectively. The dry matter accumulation and yield also showed a quadratic curve relationship with soil EC. Through model fitting，it was found that the dry matter accumulation of tomato reached the maximum at EC 2.97 mS/cm，and the weight of single fruit reached the maximum at EC 3.19 mS/cm. Multiple indicators of appearance quality and nutritional quality also showed a quadratic relationship with soil EC. The simulation results showed that the commercial fruit rate of tomato reached the maximum at EC 2.77 mS/cm，and the indicators of tomato soluble sugar，organic acid and vitamin C reached the maximum at EC 2. 94，3.15 and 3.03 mS/cm， respectively. There is a quadratic relationship between soil EC and tomato growth，yield and quality. Controlling soil EC within a reasonable range can not only ensure high yield and high quality，but also help control soil nutrient surplus and reduce environmental risks. On the premise of having integrated water and fertilizer equipment，it is more appropriate to control the soil EC in facility tomato production at about 3 mS/cm.