We report a WDM/OC/SA/TDF multifunctional integrated tapered coupler for the first time. By magnetron sputtering WTe2 on the conical region of the coupler, it can be served as a wavelength division multiplexer (WDM), output coupler (OC), saturable absorber (SA), and gain medium. The thulium-doped mode-locked fiber laser based on such integrated device was centered at 1966.6 nm with 450 fs duration and a fundamental repetition frequency of 214 MHz. The long-term operating stability and the noise feature of mode-locked laser was also characterized. At the same time, the 10th harmonic mode-lockeing (HML) at the repetition rate of 2.14 GHz was demonstrated in the cavity, to the best of our knowledge, which was the highest repetition rate reported for SA-based mode-locked fiber lasers in 2 µm region.