The invention discloses a continuous-annealing furnace roll opening refractory opening device and method. The continuous-annealing furnace roll opening refractory opening device comprises a cross and a positioning rod arranged at the center of the cross in a penetrating mode. The end of the positioning rod coincides with the center of a circular template. The opening method includes the steps that the cross is made, and a hole is punched in the center of the cross; the cross is arranged at the center of an outer ring of a roll opening; the positioning rod is arranged in a center circular hole of the cross in a penetrating mode; the center of the circular template is made to coincide with that of the positioning rod on the inner side; a circle is drawn along the periphery of the circular template, and the position of the roll opening is determined; the circular template is taken out, and opening is conducted on the refractory according to the drawn circle. The continuous-annealing furnace roll opening refractory opening device is easy to make, accurate in positioning and controllable in opening size, and the problem that it is difficult to position the center position of the roll opening in the refractory construction process is solved.