The detection of explosive nitro compounds is a key research topic in the field of environmental pollution control and public safety. The luminescent platinum complexes [Pt(ppy)(CH3CN)2]ClO4 with high fluorescence quantum efficiency was applied as fluorescent probe to detect nitrocompound 4⁃nitrotoluene (4⁃NT). The fluorescence emission intensity of [Pt(ppy)(CH3CN)2]ClO4 decreased gradually until quenching with the addition of 4⁃NT. The detection efficiency KSV of 40.2 L/mmol was obtained by fitting experimental data with Stern⁃Volmer equation, and the minimum limit of detection was 1.83×10-6 mol/L. It is confirmed by spectrum experiment and DFT calculation that the detection mechanism of 4⁃NT by [Pt(ppy)(CH3CN)2]ClO4 was investigated to be synergistic effect of energy transfer and electron transfer.