The invention relates to a crystal growth speed automatic measurement device for a photovoltaic polycrystalline silicon ingot casting furnace, which comprises a servo motor, a movement controller, a servo driver and a quartz rod. The quartz is installed above a crucible in the photovoltaic polycrystalline silicon ingot casting furnace through a mechanical device and can move along the vertical direction, the movement controller is connected with the servo motor in two directions through a movement control bus, the signal output end of the servo driver is connected with the signal input end of the servo motor through a power control line, the signal input end of the servo driver is connected with the signal output end of the servo motor through a shaft encoder feedback line, and a rotating output shaft of the servo motor is connected with the quartz rod through a transmission mechanism. The invention has the advantages of high measurement accuracy and convenient debugging and setting and can improve the quality of polycrystalline silicon ingots and realize the automation of crystal growth speed measurement.