Preparing method of aromatic polycarbonate

The invention provides a preparing method of aromatic polycarbonate. According to the invention, aromatic polycarbonate is prepared via reaction between aromatic dyhydroxy compound and carbonic acid diaryl ester. The method comprises following steps of (A) supplying the carbonic acid diaryl ester of 90 DEG C-220 DEG C to a mixing groove, wherein the supply quantity of the carbonic acid diaryl ester is 75m%-99m% of total supply quantity of the carbonic acid diaryl ester solved via target molar ratio of the aromatic dyhydroxy compound and the carbonic acid diaryl ester; (B) after the step A, supplying the aromatic dyhydroxy compound to the mixing groove whose liquid temperature is adjusted to 135 DEG C-220 DEG C; and (C) after the step (B), further supplying the carbonic acid diaryl ester to the mixing groove so as to allow the molar ratio of the aromatic dyhydroxy compound and the carbonic acid diaryl ester to be in a regulated range, thereby preparing dissolution mixture.