Hadamard multiplexing technology can effectively improve the signal-to-ratio of ion mobility spectrum, but the false peaks and other distorting phenomenon appear in Hadamard spectral, which has serious influence on the detection performance of ion mobility spectrometry(IMS). The changes of false peaks in Hadamard transform IMS are observed by changing the multiplexing parameters, and relationship between the multiplexing parameters and false peaks are analyzed. Experimental results show that variations of multiplexing parameters can change false peak position or peak profile, but they can not eliminate fundamentally false peak phenomenon of Hadamard IMS. Results further prove that the inherent defects in Hadamard multiplexinged modulation may be one of the main causes appearing the false peaks in Hadamard transform IMS.