Organic mechanochromic fluorescent materials have attracted increasing interest over the last few years. However, organic mechanochromic fluorophores reported so far usually have complicated structures and require multi-step synthesis. In this paper, a simple method to design and synthesize organic mechanochromic fluorophores with simple structures and promising mechanochromic luminescence properties is reported. Based on this method, a broad range of pyrene-based phosphonium materials with promising mechanochromic luminescence have been developed. Among all pyrene-based mechanochromic materials reported so far, tributyl(pyren-1-ylmethyl)phosphonium fluorophore 1·PF6 reported in this paper is the smallest pyrene-based mechanochromic fluorophore with the longest emission wavelength shift. The method reported in this study has shown great potential for the rapid construction of mechanochromic materials and opened a new avenue to develop novel mechanochromic materials.