The invention is applicable to the fluorescent lamp illumination field and provides a control circuit, a control system and a control method for a public place light modulation fluorescent lamp. The intelligent fluorescent lamp control system comprises an illumination signal acquisition module, an intelligent information processing module, a relay circuit and an RC filter circuit, wherein an illumination reference value is preset in the intelligent control system, the illumination signal acquisition module acquires instant illumination signal values in an illumination area every several minutes, the instant illumination signal values acquired at two continuous times are compared with the illumination reference value to control power-on and light modulation of a light modulation electronic ballast and the matching fluorescent lamp, so constant illumination in the illumination area is guaranteed, scintillation of the fluorescent lamp caused by temporary strong light illumination is avoided, and a minimum light modulation voltage signal is combined to control automatic shutdown of the fluorescent lamp at daybreak. According to the control system, the fluorescent lamp can be automatically adjusted to realize small power illumination in midnight, so practical illumination requirements and energy saving are both realized.