Chlorophyll fluorescence detection technology is widely used as a nondestructive detection method; however, the frequency band of the step pulse or the modulated pulse (PAM) used in the traditional chlorophyll fluorescence detection technology to excite signals is narrow, and a photosynthetic system is a high-order broadband system, which is difficult to excite all the dynamic characteristics. These limit the information richness contained in chlorophyll fluorescence signals. Currently available commercial chlorophyll fluorescence meters do not contain broadband excitation. The absence of this function limits the ability of emerging artificial intelligence algorithms to process complex signals for mining rich information. Thus, in this study, we developed a chlorophyll fluorescence instrument with a broadband excitation function based on the pseudorandom binary sequence (PRBS) signal. The developed instrument can measure the traditional chlorophyll fluorescence induction OJIP and PAM kinetics. The information entropy of chlorophyll fluorescence of five different plants under three different light sources confirmed that the chlorophyll fluorescence excited by PRBS has the highest information entropy. In addition, the instrument can provide chlorophyll fluorescence signals with more information and is expected to contribute to a new scientific instrument for detecting plant physiology and environmental stress.