A device for controlling output of radiofrequency ablation power configured to perform steps of: setting an ablation parameter according to an input signal in an initial state, wherein the set ablation parameter comprises at least a preset ablation power; issuing an ablation instruction to control a radiofrequency energy generator to output the preset ablation power upon receiving a start signal, recording an ablation time and acquiring an actual ablation parameter at an ablation site in real time, wherein the actual ablation parameter comprises at least an actual impedance; determining whether the actual impedance meets a preset condition; if the actual impedance meets the preset condition, issuing a sleep instruction to control the radiofrequency energy generator to pause the output of ablation power, recording a sleep time and pausing the recording of the ablation time; and if the sleep time exceeds a sleep time threshold, issuing the ablation instruction again to control the radiofrequency energy generator to continue the output of ablation power, and continuing the recording of the ablation time; wherein the preset condition comprises a first preset condition and a second preset condition, the first preset condition is R > K 1 * Rmin 1, and the second preset condition is R > K 2 * Rmin 2, and wherein R is an actual impedance, K 1 and K 2 are proportionality coefficients and meet K 1 < K 2, Rmin 1 is the lowest impedance monitored in a preset period during recording the ablation time, and wherein the preset period is a period closest to a current time and having a preset time length, and Rmin 2 is the lowest impedance monitored during recording the ablation time; determining whether the actual impedance meets the preset condition comprises determining whether the actual impedance meets any one of the first preset condition and the second preset condition; and if the actual impedance meets any one of the first preset condition and the second preset condition, determining that the actual impedance meets the preset condition. setting an ablation parameter according to an input signal in an initial state, wherein the set ablation parameter comprises at least a preset ablation power; issuing an ablation instruction to control a radiofrequency energy generator to output the preset ablation power upon receiving a start signal, recording an ablation time and acquiring an actual ablation parameter at an ablation site in real time, wherein the actual ablation parameter comprises at least an actual impedance; determining whether the actual impedance meets a preset condition; if the actual impedance meets the preset condition, issuing a sleep instruction to control the radiofrequency energy generator to pause the output of ablation power, recording a sleep time and pausing the recording of the ablation time; and if the sleep time exceeds a sleep time threshold, issuing the ablation instruction again to control the radiofrequency energy generator to continue the output of ablation power, and continuing the recording of the ablation time; wherein the preset condition comprises a first preset condition and a second preset condition, the first preset condition is R > K 1 * Rmin 1, and the second preset condition is R > K 2 * Rmin 2, and wherein R is an actual impedance, K 1 and K 2 are proportionality coefficients and meet K 1 < K 2, Rmin 1 is the lowest impedance monitored in a preset period during recording the ablation time, and wherein the preset period is a period closest to a current time and having a preset time length, and Rmin 2 is the lowest impedance monitored during recording the ablation time; determining whether the actual impedance meets the preset condition comprises determining whether the actual impedance meets any one of the first preset condition and the second preset condition; and if the actual impedance meets any one of the first preset condition and the second preset condition, determining that the actual impedance meets the preset condition.