The invention relates to a photochemical colorimetric sensor array, and concretely relates to a method for detecting various heavy metal ions with the photochemical colorimetric sensor array. The method comprises the following steps: 1, fixing several heavy metal ion indicators on a porous sensitive film to form an array; 2, carrying out multichannel analysis by means of a plurality of single channel flow cell systems which are mutually independent with each other; and 3, rapidly determining whether contents of various trace heavy metal ions of Hg, Pb, Cd, Ag, As, Ni, Cu, Zn and the like in water exceed sewage discharge standards prescribed by national standards within 10min. According to the sensor array, a color imaging device acquires changes of colors before and after the exposure of the indicators in various different heavy metal ions and constructs RGB (red, green, blue) spectrum values corresponding with the color changes into the "fingerprint" of each heavy metal ions. In the sample test process, mathematical statistic methods of cluster analysis, main component analysis and the like are adopted to contrast the fingerprint of the sample with a "fingerprint" database, so unknown heavy metal ions can be qualitatively or semi-quantitatively analyzed.