A no-load operation detection method, being applied to a vaporizer, the method comprising: obtaining (S200) vaporization parameters of a vaporization piece in real time, and calculating a variance between the vaporization parameters and a sample mean, the sample mean being a value representing a vaporization parameter level of a stable vaporization stage of the vaporizer; and determining (S400) that the vaporization piece is operated without load if the variance is greater than a preset variance value corresponding to the vaporization parameter, the preset variance value being used for distinguishing a vaporization parameter fluctuation caused by vaporization operation without load and a vaporization parameter fluctuation caused by another operation other than vaporization without load; wherein the preset variance value is obtained by: obtaining vaporization parameters when the vaporization piece is no-load operation, and calculating a no-load operation signal variance corresponding to the vaporization parameters when the vaporization piece is no-load operation; obtaining vaporization parameters of the vaporization piece when to-be-vaporized liquid is triggered to generate bubbles, and calculating a bubble signal variance corresponding to the vaporization parameters of the vaporization piece generated at the moment when the to-be-vaporized liquid is triggered to generate bubbles; and selecting a value greater than the bubble signal variance and less than the no-load operation signal variance as the preset variance value. obtaining (S200) vaporization parameters of a vaporization piece in real time, and calculating a variance between the vaporization parameters and a sample mean, the sample mean being a value representing a vaporization parameter level of a stable vaporization stage of the vaporizer; and determining (S400) that the vaporization piece is operated without load if the variance is greater than a preset variance value corresponding to the vaporization parameter, the preset variance value being used for distinguishing a vaporization parameter fluctuation caused by vaporization operation without load and a vaporization parameter fluctuation caused by another operation other than vaporization without load; wherein the preset variance value is obtained by: obtaining vaporization parameters when the vaporization piece is no-load operation, and calculating a no-load operation signal variance corresponding to the vaporization parameters when the vaporization piece is no-load operation; obtaining vaporization parameters of the vaporization piece when to-be-vaporized liquid is triggered to generate bubbles, and calculating a bubble signal variance corresponding to the vaporization parameters of the vaporization piece generated at the moment when the to-be-vaporized liquid is triggered to generate bubbles; and selecting a value greater than the bubble signal variance and less than the no-load operation signal variance as the preset variance value. obtaining vaporization parameters when the vaporization piece is no-load operation, and calculating a no-load operation signal variance corresponding to the vaporization parameters when the vaporization piece is no-load operation; obtaining vaporization parameters of the vaporization piece when to-be-vaporized liquid is triggered to generate bubbles, and calculating a bubble signal variance corresponding to the vaporization parameters of the vaporization piece generated at the moment when the to-be-vaporized liquid is triggered to generate bubbles; and selecting a value greater than the bubble signal variance and less than the no-load operation signal variance as the preset variance value. <EOS>