Mechano-responsive luminescent (MRL) polymers possessing low threshold, high contrast and good reversibility are urgently needed in fields that detect and visualize weak forces occurring in polymeric materials. Herein a supramolecular fluorescent mechanophore UPy-PDI(-OH)-UPy employing perylene diimide (PDI) that are capable of forming intramolecular excimers as the luminescent moiety and 2-urea-4[1H]-pyrimidinone (UPy) with quadruple H-bonding as the spatial constraint group is presented. MRL polyurethanes (PUs) were constructed by the integration of mechanophores into PU molecules. The MRL performances were determined by the mechanophore structures and the mechano-transduction process, which can be efficiently improved by the synergy between quadruple H-bonding and π-π stacking, and chemically bonding of the mechanophores as dynamic supramolecular chain extenders into the PU backbones. Compared with the PUs with mechanophores only based on π-π stacking or physically doping, polymers with UPy-PDI(-OH)-UPy showed enhanced sensitivities by 7.4-fold and 6.3-fold, respectively. Perceptible change from orange-yellow to yellow-green under 0~500% strain with more than 20 cycles reversibility was observed. The current work contributes a feasible strategy for improving the MRL performance of PU polymers.