To find a suitable method for evaluating electromagnetic shielding properties of metallic mesh coatings,the shielding effectiveness of a general metallic mesh coating was explored.Firstly,a set of the formulas commonly used to calculate the photoelectric characteristics of metallic mesh was analyzed.It points out that the infinite conductive material assumption of formulas is not reasonable,and these formulas can not accurately forecast the electromagnetic shielding effectiveness of thin-film metallic mesh.Then,according to the theory that the shielding effectiveness is associated with the ratio of induction voltage to resistance,a method to estimate the shielding effectiveness of thin-film metallic mesh was proposed by using the shielding effectiveness calculation formula of the continuous conductive film with the square resistance,and the estimation concrete steps were given.Finally,three specimens of thin-film metallic meshes were prepared by the laser direct writing process to test the validity of the method.The results for 30 MHz to 1 500 MHz band show that the highest electromagnetic shielding efficiency of specimens is 30 dB by the coaxial test method,and the calculation value is 31.2 dB by using the method proposed in this paper,as the calculation value is 75 dB by commonly used method.These data indicate that the commonly used electrical characteristic calculation formula of metallic mesh can not accurately evaluate the electromagnetic shielding effectiveness of thin-film metallic mesh,and the method proposed in paper is convenient,accurate and feasible.