A method for text to speech conversion and for adjusting a corpus. The method includes a text analysis step for parsing the text to obtain descriptive prosody annotations of the text based on a TTS model generated from a first corpus, a prosody parameter prediction step for predicting the prosody parameter of the text according to the result of the text analysis step, a speech synthesis step for synthesizing speech of the text based on the prosody parameter of the text, adjusting according to a target speech speed for the synthesized speech when necessary.