A three-dimensional microstrip electromagnetic material with shielding effect is designed, which can be used for debugging RF communication system. Compared with the traditional metal isolation strip, the presented material has the advantages of being light and thin, small in size and frequency adjustable. Those properties are advantageous for miniaturization and light weight design of the product.The presented material is composed of a horizontal，Electromagnetic Band Gap(EBG) structure and a vertical period “7” type structure. The EBG structure has the function of suppressing crosstalk signals in specific frequency bands. The “7” type structure can introduce the coupling current into the GND to further enhance crosstalk suppression and purify the electromagnetic environment inside the cavity. By adjusting the value of the inductance embedded in the material, the suppression of high frequency crosstalk signals at different frequencies can be achieved. Experimental results show that the presented material can achieve crosstalk signal suppression greater than 35 dBc in 15-19.25 GHz, 19.4-21 GHz, and 21.2-24 GHz bands, respectively.