The invention provides a multiple wavelength convertible tunable fiber laser based on a tapered fiber. The multiple wavelength convertible tunable fiber laser is characterized by comprising a semiconductor laser with a tail fiber, a WDM (wavelength division multiplexer), a single-mode EDF (Erbium-Doped Fiber), a fiber optic isolator, a fiber optic coupler, a fiber optic polarization controller, and a tapered fiber and tuning unit, wherein the tail fiber of the semiconductor laser is connected with the pumping end of the WDM, the output end of the WDM is connected with the output end of the fiber optic isolator through the EDF, the input end of the fiber optic isolator is connected with a port, at which the light splitting coupling ratio is 9, of the fiber optic coupler, a port, at which the light splitting coupling ratio is 1, of the fiber optic coupler is a laser output port, the input end of the fiber optic coupler is connected with the tapered fiber and tuning unit through the fiber polarization controller, the other end of the tapered fiber and tuning unit is connected with the signal port of the WDM, so as to form a closed ring cavity. The multiple wavelength convertible tunable fiber laser based on the tapered fiber, which is provided by the invention, has the advantages of simple method, low cost, compact structure, convertible multiple wavelengths, tunable wavelength, steady operation at room temperature and the like.