the present invention relates to a photochromic fluorescent polymer and a preparation method thereof , and more particularly , to a photochromic fluorescent polymer having bonds between diarylethenes and aryethene - vinylene precursors with a weight average molecular weight of 500 to 1 , 000 , 000 , which exhibits highly improved photochromic and fluorescent characteristics compared to conventional photochromic fluorescent materials and excellent solubility to organic solvents , thus being applicable for photofunctional materials and information processing device such as optical recording , optical switches , non - destructive optical recording materials .