Abstract: 【Objective】 The objective of this study is to investigate the effects of different light compensation patterns on the growth index and photosynthetic characteristics of tomato seedlings in greenhouses with the low light.【Method】Three different ways of light supplementation: CK: natural light condition; T1: 8 h discontinuous compensation of light 07: 00-11:00: 19:00-23:00 extension of morning and evening supplementation mode; T2: 12 h continuous supplemental sunlight 07: 00-19: 00 auxiliary sunlight supplement mode to exert effects pm the growth of tomato seedlings in facilities.【Result】Discontinuous illumination 8h, extension of light supply in the morning and evening (07:00-11:00, 19:00-23:00), namely, breaking the darkness under natural light condition (07:00-19:00) increased the leaf area of tomato seedlings by 16.17%, accelerated the growth rate of leaf area, significantly raised the accumulation of dry matter by 23.39%, the photosynthetic ability of tomato seedlings was increased about 22.22%, and the index of strong seedling increased remarkably.【Conclusion】Breaking the 3-4 h darkness improves seedling quality, reduced energy consumption and saved energy, which might be the optimal treatment.