What is claimed is:1. A thawing method for a thawing device, wherein the thawing device comprises a cavity defining a thawing chamber configured for placement of an object to be processed and having a forward opening, a device door disposed at the forward opening of the thawing chamber and configured to open and close the thawing chamber, a radio frequency generation module, an upper electrode plate and a lower electrode plate horizontally disposed on a top wall and a bottom wall of the thawing chamber respectively and electrically connected with the radio frequency generation module respectively, and a detection module configured to detect an incident wave signal and a reflected wave signal of an electrical connection wire connecting the radio frequency generation module to the upper electrode plate; the thawing method comprises:generating a radio frequency signal by the radio frequency generation module;obtaining the radio frequency signal; andgenerating, by the upper electrode plate and the lower electrode plate, radio frequency waves of corresponding frequency in the thawing chamber according to the radio frequency signal, and thawing the object to be processed in the thawing chamber;obtaining a voltage and a current of the incident wave signal and a voltage and a current of the reflected wave signal; andcalculating a change rate of a dielectric coefficient of the object to be processed; anddetermining a thawing progress of the object to be processed according to the change rate of dielectric coefficient to prevent the object from being excessively thawed.2. The thawing method for a thawing device according to claim 1, wherein the step of determining the thawing progress of the object to be processed comprises:obtaining the change rate of the dielectric coefficient of the object to be processed;determining whether the change rate of the dielectric coefficient of the object to be processed is greater than or equal to a first rate threshold or not; andif yes, reducing a working power of the radio frequency generation module by 30% to 40%.3. The thawing method for a thawing device according to claim 1, wherein the step of determining the thawing progress of the object to be processed comprises:obtaining the change rate of the dielectric coefficient of the object to be processed;determining whether the change rate of the dielectric coefficient of the object to be processed decreases to be less than or equal to a second rate threshold or not; andif the change rate decreases to be less than or equal to the second rate threshold, enabling the radio frequency generation module to stop working.4. The thawing method for a thawing device according to claim 3, further comprises:sending a visual and/or audible signal to a user if the change rate of the dielectric coefficient of the object to be processed decreases to be less than or equal to a second rate threshold;stopping sending of the visual and/or audible signal to the user if the object to be processed is controllably taken out of the thawing chamber.5. A thawing method for a refrigerator, wherein the refrigerator comprises a refrigerator body defining at least one containing space, at least one compartment door for opening and closing the at least one containing space separately, and a thawing device disposed in one of the at least one containing space; the thawing method comprises the thawing method for a thawing device according to claim 1.6. The thawing method for a refrigerator according to claim 5, wherein the refrigerator further comprises a power supply module for supplying power for the thawing device, and a thawing switch for controlling the start and stop of a thawing program is disposed on any one of the at least one compartment door; the thawing method for a refrigerator comprises:if the thawing switch is turned on, enabling the power supply module to start to work; andif the thawing switch is turned off, enabling the power supply module to stop working.7. The thawing method for a refrigerator according to claim 6, further comprises:if the thawing switch is turned on, the refrigeration system of the refrigerator stops providing a cooling capacity for the containing space provided with the thawing device;if the thawing switch is turned off, the refrigeration system of the refrigerator can be controlled to provide the cooling capacity for the containing space provided with the thawing device.
