The work aims to meet the requirements of laser cladding process by proposing a fast generating algorithm for laser cladding trajectory on curved surface parts. Firstly, STL format of parts was converted into triangulation format, then a set of flat sheets with a thickness of 0 and direction perpendicular to the trajectory were generated according to the theory of cut slices. Meanwhile, distance between slices was set as 30% overlap rate. Intersection points of cut slices and triangular patch were connected to form trajectory lines in the plane. For the purpose of meeting quality requirements and simplifying computation, some redundant points were removed based upon fixed value of lased defocusing distance during processing. Search interpolate algorithm was proposed to acquire final trajectory path points. At the same time, normal vector of interpolation pointson normal curved surface was determined as laser gesture. A program was developed for fast algorithm and auto generation of laser cladding trajectory by combining UG API with Visual Studio. 47 756 data was available to point cloud of the model, and 4260 trajectory points were withdrawn. 5669 points were obtained in the algorithm herein, 3861 final trajectory points were withdrawn as scanning trajectory, and search time was saved in this way. Coordinate information and normal vector information of each point acquired were input into robot program, and favorable cladding quality was acquired. The test result verifies reliability and effectiveness of this method in cladding path planning of curved surface parts.