The invention discloses a continuous casting constant-temperature ejection device and method based on electromagnetic induction heating. The continuous casting constant-temperature ejection device based on electromagnetic induction heating comprises a solenoid coil arranged on a continuous casting blank in a sleeving manner, a power control cabinet connected with the solenoid coil, an infrared thermometer collecting the head and tail temperatures of a cut continuous casting blank and a microcomputer system connected with the infrared thermometer and the power control cabinet. The continuous casting constant-temperature ejection method based on electromagnetic induction heating comprises the steps that the infrared thermometer is used for recording the head temperature T1 and the tail temperature T2 of the cut continuous casting blank and feeding back the head temperature T1 and the tail temperature T2 to the microcomputer system, the power control cabinet is started to output a start power P1 and a finishing power P2, and then the microcomputer system restarts the power control cabinet at the time interval of Tp to conduct outputting of the start power P1 and the finishing power P2of a next period. The continuous casting constant-temperature ejection device based on electromagnetic induction heating is simple in structure, and the continuous casting constant-temperature ejection method adopting the continuous casting constant-temperature ejection device can lower the temperature gradient in the length direction and radial direction of the casting blank, reduce thermal stress caused by uneven temperature distribution of the continuous casting blank before rolling and improve the structure evenness.