Preparation method of color-controllable thermoplastic polyolefin elastomer

The invention provides a preparation method of a color-controllable thermoplastic polyolefin elastomer. The preparation method provided by the invention comprises the following steps: purifying and refining a monomer raw material and a solvent, feeding the refined material, a catalyst and an antioxidant into a polymerization kettle for polymerization reaction, washing the obtained reaction liquid with deoxygenated water, and feeding the washed reaction liquid into a flash kettle for flash treatment, and finally, feeding into a multi-stage screw extruder for multi-stage vacuum devolatilization treatment to obtain the thermoplastic polyolefin elastomer. The steps are sequentially carried out, meanwhile, certain monomer raw materials are adopted in the process, and the process conditions of polymerization, flash evaporation and vacuum devolatilization treatment and the pigment adding time are controlled, so that the stability of the color of the product can be improved, and obvious chromatic aberration does not