Neonicotinoid insecticides have been widely applied in modern agriculture to improve crop productivity, but their residues have adverse impacts on the environment and human health. Hence, to address these issues, a portable self-powered/colorimetric dual-mode sensing platform was developed for the simple, rapid, precise, and sensitive on-site detection of acetamiprid (ATM) residues in vegetables. In this case, a multifunctional bioconjugate with specific recognition capability, excellent enzyme-like activity, and loading capacity is the key to the sensing design. Using an Eppendorf (EP) tube as a miniaturized laboratory, the bioconjugates and the colorimetric test strip were integrated into the EP tube, and combined with a nanozyme-based self-powered sensing platform (with an area of 1.5 × 1.5 cm2), accurate on-site detection of ATM was achieved, with detection limits as low as 2.9 fg·mL-1 (self-powered method) and 31.5 fg·mL-1 (colorimetry), respectively. Notably, we simulated the actual insecticidal situation based on the field application concentration and quantified the pesticide residues in vegetables. The relative errors of our method and the standard high-performance liquid chromatography method were 0.15% (the self-powered method) and 1.8% (colorimetry), respectively. The portable dual-mode sensing platform with high sensitivity and accuracy opened up a new avenue for the development of on-site pesticide residue analysis in the next generation of agricultural products.