The invention discloses a synthesizing device and a synthesizing process for alkyl nitrite, and belongs to the technical field of chemistry. An oxidizer is provided with a plurality of inlets for changing a connection mode with other components; and a reactor, a rectifying tower, a cooling device vaporizer and a heat exchanger are arranged to be respectively independent operation units, the independent operation units are connected with the vaporizer through a reactor tube stroke, and connected with the rectifying tower through the cooling device vaporizer and a heat exchanger liquid phase pipeline, so that the procedures of reacting, rectifying, separating and cooling the product can be carried out independently. The process comprises the steps of: (1), gasification of alkanol; (2), oxidation; (3), generation of the alkyl nitrite; and (4), separation of a by-product. The synthesizing device and the synthesizing process realize the removal and utilization of the reaction heat and gasification of the alkanol by using the heat of the reaction product. The synthesizing device and the synthesizing process for the alkyl nitrite have the advantages of high operation stability, mild reaction condition, high raw material conversion ratio, high selectivity of the product, high yield, suitability for large-scale continuous production of the alkyl nitrite and the like.