The invention discloses preparation of a light-emitting crystal material {[Cd2(tpphz)(bdc)([mu]2-OAc)2].tpphz.2H2O}n for rapid and high-sensitivity detection of permanganate ions. The preparation method comprises: adding tetrapyrido[3,2-a:2',3'-c:3'',2''-h:2''',3'''-j]phenazine, cadmium nitrate and terephthalic acid into water,stirring in N,N-dimethylacetamideto obtain a stable suspension, puttingthe suspension into a closed reaction kettle, carrying out a heating reaction, slowly cooling to a room temperature, filtering, washing, and drying to obtain the light-emitting crystal material. According to the invention, with the preparation method, the light-emitting crystal material {[Cd2(tpphz)(bdc)([mu]2-OAc)2].tpphz.2H2O}n for rapid and high-sensitivity detection of permanganate ions is obtained.