The invention mainly relates to the technical field of wood products processing, and discloses a processing method for improving the durability of birch. The processing method includes the steps of cutting, soaking, freezing, strengthening and drying; the method is simple, the strength and rigidity of the birch after being processed are improved obviously, the use range of the birch is increased,and the economic income is increased by 18.6%; birch sections are peeled and then cut, and later even processing is facilitated; the processing efficiency is improved; wood beams are placed in a preservative liquid for being soaked at high temperature, the preservative liquid is promoted to be infiltrated into the wood beams, residual bacteria and worm eggs in the wood beams are killed, mildew andmoth are avoided, and the anti-corrosion performance of the wood beams is improved; the preservative liquid is extracted from pure Chinese herbs and without any poisonous reagent, and the fact that human health is harmed in the processing and using process of the birch is avoided; after being soaked, freezing is conducted through gradually reducing the temperature, water is changed into crystalline water, the porosity between fiber of the birch is increased, the flexibility of the birch is improved, then low-temperature drying is conducted, absorption of the wood beams to a processing liquidis facilitated.