The invention provides a kit and method for quickly and quantitatively detecting small-molecular compounds. The kit comprises a test bar and a fluorescent latex particle-antibody conjugate which is placed independently, wherein a to-be-detected sample is mixed with the conjugate and added into the test bar, and is detected by a time-resolved fluorescence immunochromatographic method so as to determine whether a small-molecular compound exists or not and detect the content of the small-molecular compound. The kit has an extremely good stability, relatively high sensitivity and specificity, and is applicable to the detection of various samples.