The invention discloses a carbonatite lithology identification method, and belongs to the technical field of petroleum and gas exploration and development. The carbonatite lithology identification method includes the steps that the Ca element content and Mg element content in a rock debris sample are detected, and the ratio of Ca element content to the Mg element content is calculated according to the formula R=Ca/Mg; when R is larger than 59.4, carbonatite is pure limestone; when R is larger than 10.8 and smaller than or equal to 59.4, the carbonatite is limestone containing dolomite; when R is larger than 4.7 and smaller than or equal to 10.8, the carbonatite is dolomite limestone; when R is larger than 2.6 and smaller than or equal to 4.7, the carbonatite is calcite dolomite; when R is larger than 1.8 and smaller than or equal to 2.6, the carbonatite is dolomite containing calcite; when R is larger than or equal to 1.8, the carbonatite is pure dolomite. The carbonatite lithology identification method is easy to operate, accurate in lithology identification result, capable of correctly guiding deploy of a petroleum and gas horizontal well of a carbonatite reservoir and increasing economic benefits of petroleum and gas exploitation of the carbonatite reservoir.