The invention discloses a lightning protection device in multilevel clearance series connection. The lightning protection device in multilevel clearance series connection includes a high-voltage wireinlet end, a grounding end, a metal oxide arrester (MOA), N voltage partition capacitors, N voltage partition inductors in series connection, N-1 loop voltage partition inductors and N discharging gaps at equal intervals. Since a multilevel clearance series connection structure is adopted, the lightning protection device can be resistant to high working-frequency voltage, and a breakdown voltage value of the lightning protection device under the working-frequency voltage is extremely higher than a breakdown voltage value under lightning impulse voltage. After clearances in multilevel series connection are broken down, the metal oxide arrester starts to work, wherein the metal oxide arrester (MOA) has the characteristics of generating no continuous current under work frequency. The lightning protection device has the advantages that not only is the breakdown voltage value of the lightning protection device under the working-frequency voltage extremely higher than the breakdown voltage value under the lightning impulse voltage, but also the lightning protection device is high in work reliability, free of continuous current under the working frequency and long in service life.