Marine ship collision avoidance early warning method and system and chart plotter

The invention provides a marine ship collision avoidance early warning method and system and a chart plotter. The method comprises the steps: obtaining the navigation information of the ship, and recognizing a temporary navigation obstacle to obtain a recognition result; obtaining at least one early warning point in the current route of the ship, wherein at least one early warning point comprisesat least one of a navigation channel obstacle navigation object position point, a historical collision accident occurrence place and a temporary obstacle navigation object position point; judging whether the distance between the ship and the current early warning point is larger than the early warning distance or not according to the navigation information and the recognition result, and obtaininga judgment result, wherein the current early warning point is the early warning point closest to the ship in at least one early warning point; and if the judgment result is negative, generating earlywarning information, and p