The microrotor is an important part in a Micro-electro-mechanical System(MEMS).For designing and driving the microrotor,the theoretical arithmetic of a wave optical model is investigated.The Finite-differential Time-domain(FDTD)method is used to analyze the electric and magnetic intensity distributions of the scattered light on the surface of the microrotors,and the Maxwell's stress tensor is employed to calculate the force over the rotor surfaces.Finally,the rotor torque on rotation axis and the rotate speed are obtained base on Newton equation.The calculated results agree with the experiments in rotate speed of 200 r/min,which shows the arithmetic can satisfy the requirements of calculating the light-induced force and torque on a complex microrotor,and can used in microrotor design.作者简介：黄文浩(1944-),男,教授,博士研究生导师,主要从事SPM仪器及微纳米技术领域的研究工作.