Method for synthesizing halogenated alkanes

The invention discloses a method for synthesizing halogenated alkanes, which comprises the following steps of: adding 20 to 30 weight parts of solvent and 0.3 to 0.8 weight part of catalyst into 10 to 60 weight parts of halogens and 26 to 48 weight parts of fluorine-containing olefins, which serve as major ingredients, wherein the halogens may be a bromine simple substance or an iodine simple substance, the solvent is dimethylaniline or tetrafluoroethyl tetrafluoropropyl ether, and the catalyst is antimony pentafluoride; and reserving the pressure to between 0.05 and 0.6 Mpa by using the olefins, heating to the temperature of between 150 and 230 DEG C, and reacting under the pressure of between 0.7 and 1.8 Mpa for 3 to 8 hours, cooling to the temperature of between 30 and 40 DEG C, recovering unreacted raw materials, and rectifying under the reduced pressure to obtain a target product. In the method, the raw materials are readily available, and by-products are not generated; the process can be controlled, and