Based on the observation data of broadband tiltmeter at coastal seismic stations (Putian and Xiamen stations), this paper analyzes the noise of broadband tiltmeter using the short-time Fourier transform (STFT) method of analysis. Several noise patterns are summarized and the respective physical meaning is analyzed. The broadband tiltmeter noise mainly involves seismic co-seismic wave, typhoon interference, bad line contact, interference signal from the motherboard, etc. The results of the research can be used to track and analyze broadband tiltmeter of observation data, as well as to determine the types of broadband tiltmeter fault.