The invention relates to a loaded type molybdenum oxide catalyst for selectively oxidizing methanol to synthesize dimethoxymethane (DMM) and an application. In a stationary bed reactor, a catalyst is preformed and sieved; the size of the grain size of the catalyst occupies 1-16% of the diameter of the reactor; the filling bed height/reactor bed diameter of the catalyst is equal to 0.2-3; nitrogen is introduced at first and then oxygen and the methanol are introduced so that the methanol is bubbled and fed; and the DMM is synthesized through a reaction under a constant pressure, and the reaction time is 3-12 hours; the total feeding space velocity is 4,000-20,000 hour<-1>; a volume ratio of the oxygen to the methanol ranges from 1: 1 to 4: 1; the volume of the oxygen to the nitrogen ranges from 1:5 to 1:2; and the reaction temperature is 90-200 DEG C, so that the DMM can be obtained. The methanol is used as a raw material to prepare the DMM through selective oxidation, so that fewer by-products, high cleaning property and no pollution can be realized. Compared with the conventional catalyzing system, the catalyst preparation process is simple and the cost is small. Furthermore, the requirement on the preparation method is low, and the large-scale application is convenient.