The invention discloses a preparing method of a TiAl alloy turbine blade. The method comprises the steps that a three-dimensional model of the turbine blade is built, slicing treatment is carried out,and layer cutting data are obtained; secondly, secondly, a forming cavity of an electronic beam area selection rapid forming device is subject to vacuum pumping, and a forming substrate is preheated;thirdly, TiAl alloy powder is laid on the preheated forming substrate, and preheating is carried out; fourthly, the preheated TiAl alloy powder is subject to area selection melting scanning, and a single-layer solid piece layer is formed; fifthly, the third step and the fourth step are repeated, and an electronic beam area selection melting forming part is formed; sixthly, after cooling, the TiAlalloy turbine blade is obtained. The TiAl alloy turbine blade is prepared through the electronic beam area selecting rapid forming method, preheating of the forming substrate and the TiAl alloy powder is achieved, forming temperature of the TiAl alloy turbine blade is controlled, internal heat stress of the TiAl alloy turbine blade is reduced, deforming and breaking of the TiAl alloy turbine blade are avoided, and matching of strength and plasticity of the TiAl alloy turbine blade is enhanced.