The invention provides a tandem leader peptide for improving the expression quantity of recombinant small molecular proteins. The leader peptide meets the following general formula: Xn------X3-X2-X1-Y, wherein n is an integer between 8 and 20, X is independently selected from Glu, Asp, Pro, Ala, Gly, His, Ser and Thr, and Y is Arg or Lys. The invention also provides a method for improving the expression quantity of the recombinant small molecular proteins in yeast cells by using the tandem leader peptide. By using the leader peptide provided by the invention, the expression quantity of the small molecular proteins is effectively improved, the expression quantity of human insulin precursor fusion proteins is improved by 4.36 times, and the expression quantity of human epidermal growth factors is improved by 1.47 times; and furthermore, the small molecular fusion proteins provided by the invention can be subjected to simple protease scission to obtain small molecular proteins and do notneed to add an additional step for removing residual amino acids. Compared with an existing tandem expression technique, the small molecular proteins obtained by the method have natural N-terminals and are of important application value in the field of biological medicines.