Abstract: A monitoring method based on the detection of human ingested substances, comprises: acquiring the mass spectrum in the terminal of each matrix assisted laser ionization analysis time-of-flight mass spectrometer, and storing each mass spectrum and its corresponding identity information, sampling time and residence information when sampling in the database; obtaining the mass spectrum characteristic ion peaks of known substances and/or unknown substances in each mass spectrum; and counting the frequency of the mass spectrum characteristic ion peak of the known substance and/or the unknown substance, and early warning of the mass spectrum characteristic ion peak whose frequency is greater than the first threshold.