The invention provides an SiC fiber-reinforced TiAl-based composite with an Mo coating and a preparation method of the SiC fiber-reinforced TiAl-based composite. The preparation method comprises the steps of firstly, preparing a layer of C coating with the thickness of 2-4[mu]m on the surface of SiC fiber by using a chemical vapor deposition process; then, uniformly depositing an Mo metal coating with the thickness of 0.5-2[mu]m on the surface of the SiC fiber with the C coating by using a magnetron sputtering deposition process; and finally, preparing the SiC fiber-reinforced TiAl-based composite with the Mo coating by using a foil-fiber-foil process or a fiber coating process. The interface reaction speed of the fiber and a matrix and the consumption speed of the C coating of the fiber under a high-temperature condition are effectively reduced, and the Mo coating is excellent in thermal stability, does not participate in the interface reaction, is not diffused and can be used for effectively relieving the thermal residual stress at the interface of the composite.