An assisting apparatus for bean roasting, comprising: a microphone, being configured to sense sound in a chamber of a bean roasting device to generate an audio signal; a transceiver; a processor, being electrically connected to the microphone and the transceiver, and being configured to receive the audio signal from the microphone, generate a control signal by determining that an energy value of the audio signal crosses a threshold at a time point based on an observation time window, and transmit the control signal to the transceiver to make the transceiver transmit a prompting message to an external user equipment, wherein the control signal is configured to indicate the time point, and the time point represents one of a crack start time point and a crack end time point; characterised by the processor further being configured to retrieve the audio signal within the observation time window as a to-be-analyzed signal and to transform the to-be-analyzed signal into a frequency-domain signal to calculate a total signal energy value of the frequency-domain signal on a particular frequency band, and the energy value is the total signal energy value; the processor further being configured to take the audio signal at an initial bean roasting stage as an environment audio signal and to transform an audio frame during the initial bean roasting stage to a frequency domain to obtain an environment audio frequency signal; and the processor further being configured to calculate differences in energy values between an audio frequency signal and the environment audio frequency signal in different frequency bands, to take a frequency band having obvious energy difference as the particular frequency band, and accordingly to set the threshold corresponding to a roasting stage. a microphone, being configured to sense sound in a chamber of a bean roasting device to generate an audio signal; a transceiver; a processor, being electrically connected to the microphone and the transceiver, and being configured to receive the audio signal from the microphone, generate a control signal by determining that an energy value of the audio signal crosses a threshold at a time point based on an observation time window, and transmit the control signal to the transceiver to make the transceiver transmit a prompting message to an external user equipment, wherein the control signal is configured to indicate the time point, and the time point represents one of a crack start time point and a crack end time point; characterised by the processor further being configured to retrieve the audio signal within the observation time window as a to-be-analyzed signal and to transform the to-be-analyzed signal into a frequency-domain signal to calculate a total signal energy value of the frequency-domain signal on a particular frequency band, and the energy value is the total signal energy value; the processor further being configured to take the audio signal at an initial bean roasting stage as an environment audio signal and to transform an audio frame during the initial bean roasting stage to a frequency domain to obtain an environment audio frequency signal; and the processor further being configured to calculate differences in energy values between an audio frequency signal and the environment audio frequency signal in different frequency bands, to take a frequency band having obvious energy difference as the particular frequency band, and accordingly to set the threshold corresponding to a roasting stage. the processor further being configured to retrieve the audio signal within the observation time window as a to-be-analyzed signal and to transform the to-be-analyzed signal into a frequency-domain signal to calculate a total signal energy value of the frequency-domain signal on a particular frequency band, and the energy value is the total signal energy value; the processor further being configured to take the audio signal at an initial bean roasting stage as an environment audio signal and to transform an audio frame during the initial bean roasting stage to a frequency domain to obtain an environment audio frequency signal; and the processor further being configured to calculate differences in energy values between an audio frequency signal and the environment audio frequency signal in different frequency bands, to take a frequency band having obvious energy difference as the particular frequency band, and accordingly to set the threshold corresponding to a roasting stage.