A speech signal cascade processing method, comprising: performing offline training according to a training sample in an audio training set to obtain a first pre-augmentation filter coefficient and a second pre-augmentation filter coefficient, comprising: obtaining a sample speech signal from the audio training set, wherein the sample speech signal is a first feature sample speech signal or a second feature sample speech signal; performing simulated cascade encoding/decoding on the sample speech signal, to obtain a degraded speech signal; obtaining energy attenuation values between the degraded speech signal and the sample speech signal corresponding to different frequencies, and using the energy attenuation values as frequency energy compensation values; averaging frequency energy compensation values corresponding to the first feature sample speech signal in the audio training set to obtain an average energy compensation value of the first feature sample speech signal at different frequencies, and averaging frequency energy compensation values corresponding to the second feature sample speech signal in the audio training set to obtain an average energy compensation value of the second feature sample speech signal at different frequencies; and performing filter fitting according to the average energy compensation value of the first feature sample speech signal at different frequencies to obtain the first pre-augmentation filter coefficient, and performing filter fitting according to the average energy compensation value of the second feature sample speech signal at different frequencies to obtain the second pre-augmentation filter coefficient; obtaining a speech signal; performing feature recognition on the speech signal; if the speech signal is a first feature signal, performing pre-augmentation filtering on the first feature signal by using the first pre-augmentation filter coefficient, to obtain a first pre-augmented speech signal; if the speech signal is a second feature signal, performing pre-augmentation filtering on the second feature signal by using the second pre-augmentation filter coefficient, to obtain a second pre-augmented speech signal; and outputting the first pre-augmented speech signal or the second pre-augmented speech signal, to perform cascade encoding/decoding according to the first pre-augmented speech signal or the second pre-augmented speech signal. obtaining a sample speech signal from the audio training set, wherein the sample speech signal is a first feature sample speech signal or a second feature sample speech signal; performing simulated cascade encoding/decoding on the sample speech signal, to obtain a degraded speech signal; obtaining energy attenuation values between the degraded speech signal and the sample speech signal corresponding to different frequencies, and using the energy attenuation values as frequency energy compensation values; averaging frequency energy compensation values corresponding to the first feature sample speech signal in the audio training set to obtain an average energy compensation value of the first feature sample speech signal at different frequencies, and averaging frequency energy compensation values corresponding to the second feature sample speech signal in the audio training set to obtain an average energy compensation value of the second feature sample speech signal at different frequencies; and performing filter fitting according to the average energy compensation value of the first feature sample speech signal at different frequencies to obtain the first pre-augmentation filter coefficient, and performing filter fitting according to the average energy compensation value of the second feature sample speech signal at different frequencies to obtain the second pre-augmentation filter coefficient; obtaining a speech signal; performing feature recognition on the speech signal; if the speech signal is a first feature signal, performing pre-augmentation filtering on the first feature signal by using the first pre-augmentation filter coefficient, to obtain a first pre-augmented speech signal; if the speech signal is a second feature signal, performing pre-augmentation filtering on the second feature signal by using the second pre-augmentation filter coefficient, to obtain a second pre-augmented speech signal; and outputting the first pre-augmented speech signal or the second pre-augmented speech signal, to perform cascade encoding/decoding according to the first pre-augmented speech signal or the second pre-augmented speech signal.