Various new conductive materials with exceptional properties are utilized for the preparation of electronic devices. Achieving ultra-high conductivity is crucial to attain excellent electrical performance. However, there is a lack of systematic research on the impact of conductor material thickness on device performance. Here, we investigate the effect of conductor thickness on power transmission and radiation in radio-frequency (RF) and microwave electronics based on MXene nanosheets material transmission lines and antennas. The MXene transmission line with thickness above the skin depth exhibits a good transmission coefficient of approximately −3 dB, and the realized gain of MXene antennas exceeds 2 dBi. Additionally, the signal transmission strength of MXene antenna with thickness above the skin depth is higher than 5-μm MXene antenna approximately 5.5 dB. Transmission lines and antennas made from MXene materials with thickness above the skin depth exhibit stable and reliable performance, which has significant implications for obtaining high-performance RF and microwave electronics based on new conductive materials.