As a method to measure the vibration intensity on a thin plate, wave composition method is presented. Sensors are arranged on the circle, so measurement is easier with this method than with traditional finite difference method, it arranges them on an array. Good measurement accuracy is expected because spatial derivation is performed algebraically employing Fourier transform. Simulations of estimation error are done for plane wave field and divergent wave field. Error is small for smaller measurement circle, however, under measurement error at sensors (unavoidable at practical measurement), estimation with smaller measurement circle suffers from this measurement error. Larger circle diameter is suitable for robust measurement. Comparison with traditional finite difference method is performed. Present method shows good accuracy for broad frequency range.