The invention relates to a preparation method for low-carbon photocuring single-side moisture transport finishing agent. The method comprises the following steps: (1) a precursor is poured in a mixture of ethanol and de-ionized water, and is acutely stirred at the temperature of 10-40 DEG C; and (2) catalyst-ammonia water is slowly dripped to stir, then different-chain-length alkyl containing an azide group or siloxane of aromatic hydrocarbon is added to continuously stir in order to obtain low-carbon and energy-conservation single-side moisture transport finishing agent containing an azide functional group. The finishing agent has stable properties; finished fabrics obtain excellent single-side moisture transporting performance and durability, and need no heat baking, so that a large amount of energy is saved; the finishing agent accords with the national modern economic development theme of environmental protection and low energy consumption, and has wide market application prospect and excellent social benefit.