An electronic cigarette, comprising: a sleeve (10, 20, 30, 40), an end of which is provided with a mouthpiece (15, 25), and the other end of which is provided with an analog cigarette end (16, 26); a battery module (11, 21), arranged in the sleeve (10, 20, 30, 40); a reservoir (12, 22, 32), formed in the sleeve (10, 20, 30, 40) and configured to contain tobacco liquid; an atomizing unit (13, 23, 33), arranged in the sleeve(10, 20, 30, 40), wherein the atomizing unit (13, 23, 33) is electrically connected to the battery module (11, 21), and is configured to atomize the tobacco liquid to form aerosol; and a blocking module (14, 24, 44), arranged in the sleeve (10, 20, 30, 40) and configured to isolate the battery module (11, 21) and the reservoir (12, 22, 32), wherein a ventilation hole (140, 240, 340) is disposed on the blocking module (14, 24, 44) for achieving air communication between the atomizing unit (13, 23, 33) and the battery module (11, 21); wherein the blocking module (14, 24, 44) is switchable so as to switch the ventilation hole (140, 240, 340) between a closed state and an open state, the ventilation hole (140, 240, 340) is in the closed state before a first use of the electronic cigarette; when the electronic cigarette is used, the blocking module (14, 24, 44) is switched to make the ventilation hole (140, 240, 340) in the open state, so as to allow air to enter the ventilation hole (140, 240, 340) and pass through the atomizing unit (13, 23, 33) to carry the aerosol generated by the atomizing unit (13, 23, 33); characterised in that the blocking module (14, 24, 44) comprises a plugging block (144, 244, 344) plugged in the ventilation hole (140, 240, 340) such that the ventilation hole (140, 240, 340) is in the closed state before the first use of the electronic cigarette; wherein the ventilation hole (140, 240, 340) is switched to be in the open state when the plugging block (144, 244, 344) is removed from the ventilation hole (140, 240, 340) and the ventilation hole (140, 240, 340) remains the open state during the electronic cigarette is being used. a sleeve (10, 20, 30, 40), an end of which is provided with a mouthpiece (15, 25), and the other end of which is provided with an analog cigarette end (16, 26); a battery module (11, 21), arranged in the sleeve (10, 20, 30, 40); a reservoir (12, 22, 32), formed in the sleeve (10, 20, 30, 40) and configured to contain tobacco liquid; an atomizing unit (13, 23, 33), arranged in the sleeve(10, 20, 30, 40), wherein the atomizing unit (13, 23, 33) is electrically connected to the battery module (11, 21), and is configured to atomize the tobacco liquid to form aerosol; and a blocking module (14, 24, 44), arranged in the sleeve (10, 20, 30, 40) and configured to isolate the battery module (11, 21) and the reservoir (12, 22, 32), wherein a ventilation hole (140, 240, 340) is disposed on the blocking module (14, 24, 44) for achieving air communication between the atomizing unit (13, 23, 33) and the battery module (11, 21); wherein the blocking module (14, 24, 44) is switchable so as to switch the ventilation hole (140, 240, 340) between a closed state and an open state, the ventilation hole (140, 240, 340) is in the closed state before a first use of the electronic cigarette; when the electronic cigarette is used, the blocking module (14, 24, 44) is switched to make the ventilation hole (140, 240, 340) in the open state, so as to allow air to enter the ventilation hole (140, 240, 340) and pass through the atomizing unit (13, 23, 33) to carry the aerosol generated by the atomizing unit (13, 23, 33); characterised in that the blocking module (14, 24, 44) comprises a plugging block (144, 244, 344) plugged in the ventilation hole (140, 240, 340) such that the ventilation hole (140, 240, 340) is in the closed state before the first use of the electronic cigarette; wherein the ventilation hole (140, 240, 340) is switched to be in the open state when the plugging block (144, 244, 344) is removed from the ventilation hole (140, 240, 340) and the ventilation hole (140, 240, 340) remains the open state during the electronic cigarette is being used.