The utility model provides a detector for a solidification end position of a bloom continuous casting billet. The detector comprises pressure sensors and a displacement sensor, wherein the pressure sensors comprise a cylinder upper cavity pressure sensor and a cylinder lower cavity pressure sensor, and the cylinder upper cavity pressure sensor and the cylinder lower cavity pressure sensor are respectively arranged on the upper cavity and the lower cavity of a cylinder at the top end of a withdrawal and straightening machine; the displacement sensor is arranged at the top end of the cylinder and extends to the interior of the cylinder through a through hole of a cylinder piston so as to be connected with a pull rod of the withdrawal and straightening machine. By utilizing the detector for the solidification end position of the bloom continuous casting billet, provided by the utility model, the solidification end position of the bloom continuous casting billet can be monitored in real time on line; the detector for the solidification end position of the bloom continuous casting billet has the characteristics that the destructiveness is low, the detection is fast, and the accuracy is high.