Supporting leg, supporting leg mounting structure and microwave oven

The utility model provides a supporting leg, which comprises an elastic main leg body, an elastic auxiliary leg body, a connecting piece and a connecting piece, wherein the upper section of the elastic main leg body is provided with an anti-falling section, and the lower section of the elastic main leg body is provided with a leg pad section; a vertical expansion hole is formed in the main leg body, the lower end of the expansion hole penetrates through the main leg body, and the expansion hole at least extends into the fixed section; and the expansion piece is inserted into the expansion hole to enable the fixed section to expand towards the outer side. The supporting leg is simple and reliable in structure, not prone to loosening, convenient to produce and assemble, capable of being used for a long time and not prone to damage, the elastic main leg body enables a small amount of size errors to be automatically made up through elastic deformation of the elastic main leg body in the using process, and it is g