A portable device for detecting the nutrition level of a plant includes an outer casing and a detection circuit. The outer casing includes belt pulleys, a cam, upper and lower clamping plates. The detection circuit is arranged in the outer casing and realizes an electric signal processing function and a display function. The portable device for detecting the nutrition level of the plant has the following beneficial effects: the device can be used for analyzing whether nutrient elements in crops are deficient or excessive, which is taken as the basis for accurate fertilization, and the device has low detection cost, high real-time capability, small size and is portable.
