The invention relates to a plate spring quality detection device for achieving on-line plate spring rolling data measuring. Conveying rollers are arranged on a machine frame and subjected to transmission through a roller bed driving motor. A servo motor is arranged at the tail end of the machine frame and connected with a synchronous belt driving wheel, the synchronous belt driving wheel is connected with one end of a synchronous belt, and the other end of the synchronous belt is connected with a synchronous belt tension mechanism. The synchronous belt is connected with a moving traction platform, the inner side of the lower portion of the moving traction platform is connected with a linear guide rail slide block, the linear guide rail slide block is installed in a measuring guide rail on the side face of the machine frame, and a plate spring positioning and clamping mechanism is fixed to the top of the moving traction platform. The front end of the machine frame is provided with a front alignment mechanism, a rear alignment mechanism is arranged by being matched with the front alignment mechanism, the portion, between the front alignment mechanism and the rear alignment mechanism, of the machine frame is correspondingly provided with an upper laser range finder and a lower laser range finder, and an air cooling pipe is fixed to the position corresponding to a measuring slice. Through the plate spring quality detection device, on-line detection of the quality of a high-temperature plate spring rolled slice can be achieved, the detection efficiency is high, the detection precision is improved, and the detection accuracy rate is ensured.