Preparation method of TiAl alloy investment casting shell

The invention provides a preparation method of a TiAl alloy investment casting shell. The preparation method of the TiAl alloy investment casting shell aims at solving the problems of high cost and heavy interface reaction of the existing TiAl alloy investment casting ceramic shell. The method comprises the steps of 1, preparing the slurry of a surface layer, 2, preparing a surface-layer shell, 3, preparing an impending surface-layer shell, 4, preparing a back-layer shell, 5, sealing, and 6, dewaxing and roasting. The preparation method is used for remarkably reducing the degree of the TiAl alloy investment casting interface reaction and achieving the purposes of reducing the TiAl alloy investment casting cost and reducing the interface reaction. The shell casting is bright in surface without obvious sand burning; the thickness of the interface reaction is about 30 microns and the interface reaction degree is weaker than that of the traditional shell.