Disclosed is a wheel flange planeness detection device, comprising a frame, a lifting cylinder, a lifting platform, guide posts, a support frame, a servo motor, a bearing seat, a shaft, a bearing, a rotating platform, guide rails, a sliding block, a small chain wheel, a large chain wheel, a clamping cylinder, a chain wheel driving motor, a left sliding plate, rotating shafts, rotating wheels, a visual sensor, clamping guide rails, gear rack structures, a right sliding plate, intelligent dial indicators, a support plate, a linear motor and a motor support. The device may monitor the state of flange planeness in an automatic production line in real time; when the flange planeness is out of tolerance, the device may immediately give an alarm, and the technologist adjusts the machining process in time after receiving the alarm, thereby avoiding a large batch of rejects.