An　interpatient　classification　method　using　the　second　lead　for　the　Association　for　the　Advancement　of　Medical　Instrumentation　(AAMI)　standard　is　introduced.　This　study　includes　three　parts.　In　the　first　part,　the　fuzzy　matching　algorithm　is　used　to　locate　the　key　waveform　points　of　Electrocardiogram　(ECG)　data.　In　the　second　part,　the　feature　engineering　algorithm　is　used　to　filter　the　extracted　data　sets.　In　the　third　part,　the　random　forest　model　is　carried　out　to　realize　the　five　classifications　of　heart　disease　by　the　selected　features.　The　final　precision,　recall,　and　F1-score　are　91%,　89%,　and　90%,　respectively.　©　2021　IEEE.