A method for amplifying and dynamically adjusting an optical signal is provided in the present invention, which includes: a first optical tap splitting out a small part of the optical signal, which is converted into an electric signal via a first optical detector and is then output to a high speed gain control circuit, in proportion from an uplink burst optical signal, and outputting a remainder of the optical signal to an optical amplifier; the high speed gain control circuit dynamically adjusting the control signal loaded on the optical amplifier according to the input electric signal which varies with uplink burst slots; and the optical amplifier dynamically adjusting a gain value according to the loaded control signal to make peak powers of the output uplink optical signals in different burst slots equal, thus achieving output power equalization.