The invention provides a zinc-cluster porous luminescent complex. The chemical formula is [NH2(CH3)2][Zn3(BTC)2(BTA)].2DMF; the complex has a porous three-dimensional network structure; and one-dimensional channels are formed in c-axis directions of crystals, and dimethyl formamide molecules are filled in the channels. The preparation method comprises the following steps of: mixing trimesic acid, 1H-benzotriazole, zinc nitrate and N,N-dimethylformamide, performing crystallization reaction, naturally cooling to room temperature, and filtering a solution to obtain colorless transparent bulk crystals, namely single crystals of the complex. The invention has the advantages that: the preparation method is simple is process and easy to implement; the obtained crystals are high in purity, yield and reproducibility; the complex can produce fluorescence, has a fluorescence enhancement or quenching effect on copper and barium metal ions, can be used as a fluorescent material for preparing fluorescent probes, and is used for detecting metal ions in environments or foods; and the detection method is simple and higher in selectivity, and has a broad application prospect.