The invention relates to an agent for loop-mediated isothermal amplification. The agent comprises at least one of nanoparticles, dithiothreitol, peptide bovine serum, tetramethylammonium chloride andtrehalose. The invention also relates to a kit containing the abovementioned agent and the application thereof. The kit further comprises a 10x constant-temperature buffer, a dNTP mixture, MgSO4, a Bst DNA polymerase, an indicator and water; a loop-mediated isothermal amplification reaction system prepared through the kit comprises the following components by final concentration: 0-10mg / mL of nanoparticles, 0-10M of dithiothreitol, 0-10g / mL of peptide bovine serum, 0-100mM of tetramethylammonium chloride, 0-50mM of trehalose, 1.0-3.0mM of dNTP mixture, 4-10mM of MgSO4, and 0.1-0.5U / uL of DNA polymerase. According to the agent, the kit and the application thereof, the detection quality is ensured while the problem of high cost of an LAMP agent is high is solved; the kit has the same detection effect as an imported agent; the sensitivity, the specificity and the stability meet the clinical test demand; the detection cost is greatly decreased; and the application prospect is good.