The invention discloses a method for correcting the draught value of a ship. The method comprises the following steps: Step S10, reading draught readings of staff gauges of a bow, a midship and a stern of the ship as TF'', TM'' and TA'' separately; S20, calculating the trimming angle alpha of the ship, as well as theoretical draught values TF', TM' and TA' of the bow, the midship and the stern; Step S30, calculating a mean draught value Tmean of the ship and a draught correction value delta according to the following formulas: Tmean=(TF'+n*TM'+TA')/(n+2), and delta=(TF'+TA')/2-Tmean, wherein n is a natural number ranging from one to ten; and Step40, calculating an actual draught value of the bow according to the formula: TF=TF'-delta, and an actual draught value of the stern according to the formula: TA=TA'-delta. According to the method, the staff gauge readings, the mean draught value, the theoretical draught values and the draught correction value delta of the ship can be obtained, the actual draught value of the ship is the difference between the theoretical draught values and the draught correction value, so that the draught readings of the staff gauges of the ship are converted into draught values at a bow vertical line and a stern vertical line of the ship, and the precision is high.