雷声大，雨点小 (雷聲大，雨點小) léishēng dà, yǔdiǎn xiǎo

léishēng dà, yǔdiǎn xiǎo phrase loud thunder, but only tiny drops of rain; a lot of talk, but no action; action speaks louder than words
Domain: Proverb 谚语
Notes: (CC-CEDICT '雷聲大，雨點小')