The invention discloses an automatic curtain based on light intensity sensing. The automatic curtain comprises a shading module, a dimming module, a photosensitive module, a control module, a power supply module and a wireless receiving module; the shading module comprises a shading rotating shaft, a shading curtain cloth and a shading motor; the dimming module comprises multiple dimming units from outside to inside, and each dimming unit comprises a dimming rotating shaft, a dimming curtain cloth and a dimming motor; the photosensitive module comprises a first photosensitive sensor and a second photosensitive sensor; the first photosensitive sensor is arranged outside the shading cloth, and the second photosensitive sensor is arranged on the innermost side in the dimming module; the wireless receiving module is used for receiving the light intensity set by the outside world and transmits the light intensity to the control module. At work, the control module controls the shading motorand all dimming motors to work according to the light intensity received by the wireless receiving module, sensing data of the first photosensitive sensor and sensing data of the second photosensitivesensor. The automatic curtain is simple in structure and convenient to use, and light regulation has layering.