The invention discloses a single-channel ink quantity limiting method for a color ink jet printer. The method comprises the steps that firstly, output color targets of a cyan channel, a pinkish redchannel, a yellow channel and a black channel are designed; secondly, the color control function and the ink quantity limiting function of the color ink jet printer are closed, and the output color targets are printed; thirdly, the chromaticity and brightness of all color lumps of the output color targets are measured, and the saturability of each color lump is obtained according to the chromaticity; fourthly, maximum ink quantity thresholds of all the channels are obtained according to the rule of change between dot percentage and brightness and saturability; fifthly, output ink quantities corresponding to all the channels are controlled according to the input dot percentage and the maximum ink quantity thresholds of all the channels. By means of the single-channel ink quantity limiting method, while the output ink quantities are controlled accurately, the output color gamut of the printer can be maximized, the problems of wrinkling, ink piling, overflow and the like caused by an over-limit ink quantity are solved, and therefore the color output capability of the printer is improved.