The invention provides a method for secretory expression of super-folded green fluorescent protein mediated heterologous protein in escherichia coli. The method includes steps: 1) constructing a secretory expression carrier pET23a / sfGFP-GFP taking sfGFP (super-folded green fluorescent protein) as a secretory tag; 2) constructing a heterologous protein gene recombinant expression carrier; 3) respectively converting and fusing the expression carriers to escherichia coli competent cell Rosetta Blue to obtain a recombinant strain; 4) expressing, culturing and performing functional verification; 5) performing high-density fermentation of the recombinant strain. According to secretion characteristics of the super-folded green fluorescent protein, extracellular secretory expression of the heterologous protein in escherichia coli in a fusion protein form is realized without mediating through signal peptides, an operation process is simplified, high autocrine performance is realized, functional influences of tag protein on target protein are avoided, expression conditions can be quickly optimized, target protein yield is increased, and the method is suitable for large-scale production. In addition, an application field of sfGFP is expanded, and a novel method is provided for extracellular secretory expression of the heterologous protein in escherichia coli.