Smoke interference is an important means of defense against incoming photoelectric guided weapons.Smoke interference effectiveness is closely related to actual meteorological conditions,distribution density,defense target characteristic.The real-time measurement of smoke extinction properties is basic requirements of smoke interference effectiveness evaluation.The laser Mie scattering mechanism of smoke particles were analyzed,and the tomography fault inversion smokescreen extinction coefficient model of the laser backward scattering was established.Through the development of the tomography measuring system,smoke extinction coefficients were measured after three kinds of typical smoke agent smoke.The results show that the tomography of the laser backward scattering can effectively measure smoke extinction characteristics.The result can provide a support for real-time measurement and performance evaluation of smoke interference effect.