The invention relates to a heat treatment method for improving the fatigue crack growth rate of a 2xxx-T3 plate. The heat treatment method is characterized by comprising the following steps that firstly, alloy is burdened, smelted and cast into a cast ingot; secondly, homogenizing heat treatment is conducted on the cast ingot, wherein the cast ingot is heated to 490-510 DEG C from the room temperature at the average heating rate of 10-400 DEG C/h or for 1-48 h, heat preservation is conducted for 1-60 h, and furnace cooling or air cooling is conducted; thirdly, preheating and heat preservation treatment are conducted, wherein the room temperature is increased to the temperature of 470-500 DEG C at the average heating rate of 10-400 DEG C/h or for 1-48 h, and heat preservation is conducted for 1-20 h; fourthly, hot rolling is conducted, the hot rolling beginning temperature is 460-495 DEG C, and the finish hot rolling temperature is higher than 250 DEG C; fifthly, annealing and/or solution treatment are/is conducted; and sixthly, finishing is conducted, natural aging is conducted, and a T3-state plate is obtained. According to the common application of the key homogenizing technology and the key preheating and heat preservation technology before hot rolling, the area fraction of a second large phase in an alloy structure before hot rolling can be effectively controlled, and therefore the value da/dN of the fatigue crack growth rate of the 2xxx-T3 plate is obviously improved.