A protective case for a mobile phone and a tablet computer, comprising: a main body and a rotatable bottom support located at one end of the main body ; a surface support configured to match with the bottom support disposed on a second end of the main body , and a supporting plate disposed on the surface support ; wherein the bottom support comprises: - a limiting surface configured to match with the surface support , - elastic positioning parts disposed on the bottom support , - positioning points , wherein the bottom support and the surface support are positioned in a connecting process by the positioning points , - and a plurality of limiting columns to position the surface support; wherein the surface support matches with the bottom support in such a way that form into a whole with the bottom support ; the plurality of the limiting columns are uniformly disposed on an upper end of the limiting surface ; and wherein the elastic positioning parts are made of plastic so a production and assembly error is solved by utilizing free elasticity of the plastic; the positioning points are uniformly disposed on the bottom support outside of the elastic positioning parts , wherein the supporting plate is hinged with the surface support for adjusting the supporting angles arbitrarily, a hinged position of the supporting plate and the surface support is connected by a telescopic mechanism for adjusting a distance between the supporting plate and the surface support . a main body and a rotatable bottom support located at one end of the main body ; a surface support configured to match with the bottom support disposed on a second end of the main body , and a supporting plate disposed on the surface support ; wherein the bottom support comprises: - a limiting surface configured to match with the surface support , - elastic positioning parts disposed on the bottom support , - positioning points , wherein the bottom support and the surface support are positioned in a connecting process by the positioning points , - and a plurality of limiting columns to position the surface support; - a limiting surface configured to match with the surface support , - elastic positioning parts disposed on the bottom support , - positioning points , wherein the bottom support and the surface support are positioned in a connecting process by the positioning points , - and a plurality of limiting columns to position the surface support; wherein the surface support matches with the bottom support in such a way that form into a whole with the bottom support ; the plurality of the limiting columns are uniformly disposed on an upper end of the limiting surface ; and wherein the elastic positioning parts are made of plastic so a production and assembly error is solved by utilizing free elasticity of the plastic; the positioning points are uniformly disposed on the bottom support outside of the elastic positioning parts , wherein the supporting plate is hinged with the surface support for adjusting the supporting angles arbitrarily, a hinged position of the supporting plate and the surface support is connected by a telescopic mechanism for adjusting a distance between the supporting plate and the surface support . <EOS>