A method for processing a lost frame of an audio signal, wherein the method comprises: determining an initial high-band signal of a current lost frame; determining a gain of the current lost frame; determining gain adjustment information of the current lost frame, wherein the gain adjustment information comprises at least one of the following: a class of a frame, a low-band signal spectral tilt of a frame, a low-band signal energy of a frame, and a quantity of consecutive lost frames, wherein the quantity of consecutive lost frames is a quantity of consecutive frames that are lost until the current lost frame; adjusting the gain of the current lost frame according to the gain adjustment information, to obtain an adjusted gain of the current lost frame; and adjusting the initial high-band signal according to the adjusted gain, to obtain a high-band signal of the current lost frame; characterized in that, after the determining gain adjustment information of the current lost frame, the method further comprises: determining an initial excitation adjustment factor according to a subframe gain and a global gain of the current lost frame; adjusting the initial excitation adjustment factor according to the gain adjustment information, to obtain an adjusted excitation adjustment factor; and the adjusting the initial high-band signal according to the adjusted gain, to obtain a high-band signal of the current lost frame comprises: adjusting the initial high-band signal according to the adjusted gain and the adjusted excitation adjustment factor, to obtain the high-band signal of the current lost frame. determining an initial high-band signal of a current lost frame; determining a gain of the current lost frame; determining gain adjustment information of the current lost frame, wherein the gain adjustment information comprises at least one of the following: a class of a frame, a low-band signal spectral tilt of a frame, a low-band signal energy of a frame, and a quantity of consecutive lost frames, wherein the quantity of consecutive lost frames is a quantity of consecutive frames that are lost until the current lost frame; adjusting the gain of the current lost frame according to the gain adjustment information, to obtain an adjusted gain of the current lost frame; and adjusting the initial high-band signal according to the adjusted gain, to obtain a high-band signal of the current lost frame; characterized in that, after the determining gain adjustment information of the current lost frame, the method further comprises: determining an initial excitation adjustment factor according to a subframe gain and a global gain of the current lost frame; adjusting the initial excitation adjustment factor according to the gain adjustment information, to obtain an adjusted excitation adjustment factor; and the adjusting the initial high-band signal according to the adjusted gain, to obtain a high-band signal of the current lost frame comprises: adjusting the initial high-band signal according to the adjusted gain and the adjusted excitation adjustment factor, to obtain the high-band signal of the current lost frame. a class of a frame, a low-band signal spectral tilt of a frame, a low-band signal energy of a frame, and a quantity of consecutive lost frames, wherein the quantity of consecutive lost frames is a quantity of consecutive frames that are lost until the current lost frame; adjusting the gain of the current lost frame according to the gain adjustment information, to obtain an adjusted gain of the current lost frame; and adjusting the initial high-band signal according to the adjusted gain, to obtain a high-band signal of the current lost frame; characterized in that, after the determining gain adjustment information of the current lost frame, the method further comprises: determining an initial excitation adjustment factor according to a subframe gain and a global gain of the current lost frame; adjusting the initial excitation adjustment factor according to the gain adjustment information, to obtain an adjusted excitation adjustment factor; and the adjusting the initial high-band signal according to the adjusted gain, to obtain a high-band signal of the current lost frame comprises: adjusting the initial high-band signal according to the adjusted gain and the adjusted excitation adjustment factor, to obtain the high-band signal of the current lost frame.