A chalcogenide-tellurite composite microstructed optical fiber (MOF) has been proposed and designed in this paper. The fiber has a flattened near-zero dispersion curve around 2.5 μm and has two zero dispersion wavelengths(ZDWs) in close. It also shows low confinement loss and single mode operation properties. Numerical simulation has been used to predict the supercontinuum spectra obtained from the designed fiber. Simulation results show that a widely supercontinuum spectrum covering from 1.8 to 6.0 μm can be generated by pumping pulses of energy below 10pJ/pulse.