FY-3G is the first Chinese low-inclination-orbiting precipitation satellite, launched on April 16, 2023. It aims at monitoring global precipitation within the latitudinal range of 50°S-50°N. The MWRI-RM (Microwave Radiation Imager for the Rainfall Mission) is a principal instrument onboard the FY-3G. Unlike previous microwave imagers on FY-3B/C/D, MWRI-RM has 26 channels, including atmospheric window channels 1-10 with frequencies ranging from 10 to 89 GHz, temperature sounding channels 11-18 around 54 GHz, light precipitation detection channels 19-22 located at 118 GHz and channel 23 at 165.5±0.75 GHz, and humidity sounding channels 24-26 near 183 GHz. This study reports on the striping noise present in MWRI-RM observations across all channels. The magnitude of striping noise in the brightness temperature observations for MWRI-RM channels with their frequencies below 36.5 GHz is the smallest (mostly within ±0.3 K), while for other channels(89-183 GHz), it ranges from ±0.5 to ±1 K. The striping noise mitigation method employed in this study prevents sharp variations of brightness temperatures at land-sea boundaries and cloud edges from being erroneously identified as striping noise, thus avoiding any impact on reconstructed brightness temperature observations. The striping noise mitigation is a necessary step for precipitation retrieval from and data assimilation of MWRI-RM brightness temperature observations.