Abstract: The non-uniform snow load on a complex roof is one of the most important factors that should be considered by a designer. The snow codes of China, America, Canada and Europe were compared, and the difference of equations and roof types were analyzed. Snowdrift simulation was carried out by using edible salt, silica sand, alum and dry sawdust of pine in a wind tunnel. The results show that in the four codes, snow loading is expressed by the product of reference snow pressure and coefficients in different types, and that fewer parameters on environment are considered in Chinese code, compared with other codes. As the adhesive force of alum is too strong, it is difficult to produce a continuous drift motion in a wind tunnel test for this material. The simulation effect of the dry sawdust of pine is not as good as its density is too small. The edible salt and silica sand with high density have relatively good simulation effects. In order to attain non-uniform snow loading on a structure in a design period by wind tunnel tests, the field observation with multiply parameters, the collection of meteorological data in detail, similarity criterion and parameter selection research are necessary as a basic research.