The invention belongs to the technical field of photoelectric measurement, relating to a chlorophyll measuring apparatus. A mechanical structure part of the device comprises a light source, a T-shapedobject stage and a sensor seat, wherein the light source contains a white light LED, the bottom of the sensor seat is provided with a color sensor, and a photophobic probe structure is formed by thelight source, the object stage and the sensor seat; a circuit part of the apparatus comprises a light source module driving the white light LED, a digital signal sensor module and a digital signal processing and controlling module; the digital signal sensor module collects the light intensity information of red light, green light and blue light in probe light transmitting an object to be measuredat different time by the color sensor, and transforms light intensity signals into square signals for outputting; the digital signal processing and controlling module captures the three square signalsso as to obtain frequency signals representing the light intensity information of red light, green light and blue light, and simultaneously calculates the chlorophyll content in the objected to be measured according to the multiplex linear regression equation between the three frequency signals and the chlorophyll content. The apparatus has the advantages of simple and stable lighting source, relatively accurate measured chlorophyll content and the like.