The invention provides a line lightning protection area treatment method based on risk assessments, and belongs to the lightning protection technical field; the method comprises the following steps: obtaining a direct supply line power failure loss sum; obtaining a connection line power failure loss sum; obtaining a history lightning stroke trip-out rate, and combining the direct supply line powerfailure loss sum and the connection line power failure loss sum so as to obtain a lightning protection risk value of the area lines; averagely investing each line, obtaining an amplitude value reduced proportion, and carrying out lightning protection investment of different sum levels on each line in the area according to the amplitude value reduced proportion. The method obtains the lightning protection risk value of each line in the area through risk evaluations, averagely invests each line so as to obtain the amplitude value reduced proportion, carries out lightning protection investment of different sum levels on each line in the area according to the amplitude value reduced proportion, thus effectively utilizing lightning protection budgets, and realizing lightning protection purposes in the maximum level.