A tunable multi-wavelength EDFL with precise wavelength interval control is reported theoretically and experimentally in this paper. It is made up of MZI filter and Sagnac filter, and supplemented by four-wave-mixing effect. Compared with other filters, the proposed MZI filter based on the fused taper technology can change the wavelength interval more flexibly. The experiment result shows that the wavelength tuning can be achieved and the tuning range can reach ~15nm. Moreover, the variation in the number of wavelengths are also realized. The maximum SMSR can reach 39dB.