Obstacle avoidance early warning method for tower crane

The invention provides an obstacle avoidance early warning method for a tower crane, and relates to the field of tower crane obstacle avoidance. The obstacle avoidance early warning method based on the tower crane comprises the following steps: Step 1, establishing a coordinate system by taking a geometric center of a tower crane support column as a pole and taking a magnetic declination zero line as an OX axis, Step 2, setting a length value of a tower crane support arm by taking a direction which is the same as a gravity direction as an OY axis, and Step 3, mounting a distance sensor on a lifting hook. The geometric center of the tower crane supporting column is used as the original point, errors generated in the measuring process of a cab are avoided, the early warning accuracy is improved, the magnetic declination and the distance sensor are used, correction of obstacles can be achieved in the environment changing process, the early warning accuracy is improved, and the safety of a cab is improved. And a