The invention provides a method for accurately measuring a tiny force and a
force constant of a micro-
cantilever, belonging to the field of nanometer measurement. In this method, the two ends of a nanomaterial are fixed on two fulcrums, and a small axial pulling force T is applied to the nanomaterial; on the side of the nanomaterial, an
electrode is placed in the middle of the nanomaterial, and a The alternating
voltage excites the nanomaterial to make it resonate, and the
natural frequency f of the nanomaterial is measured; according to the material characteristics and geometric characteristics of the nanomaterial and the boundary conditions of the nanomaterial, the
natural frequency of the nanomaterial is calculated from the vibration equation. The relationship between the axial tensile force received, that is, the f-T curve of the nanomaterial; according to the
natural frequency f measured above, the magnitude of the
micro tensile force T is obtained. The method is further used to measure the micro-deflection force of the micro-
cantilever when it is deflected, and the
force constant of the micro-
cantilever is measured in combination with the measurement of the deflection displacement. The invention can be used to develop an instrument for accurately measuring tiny forces of the order of pico-newtons or even flying newtons.