In order to give consideration to the copyright protection and content authentication of vector geographic data

and ensure the accuracy of data

a multiple watermarking algorithm is proposed

which has no effect on the data accuracy and includes zero-watermarking and fragile watermarking. Based on vector element nodes

the algorithm divides the vector geographic data into different degrees of blocks by point constraint according to requirements. A large capacity zero-watermarking algorithm with two main processes is put forward to protest the copyright of data

The Douglas algorithm and the Delaunay triangulation network are adopted to extract feature points and feature information from the data

and then the watermarking image scrambled by Arnold algorithm does xor with the feature information. By spatial sorting and zero-bit dynamic expansion

a non-destructive embedded fragile watermarking algorithm is used to authenticate data content. The experimental results show that the zero-watermarking algorithm can resist robustly against the common map attacks and combination attacks; the fragile watermarking algorithm can effectively achieve accurate authentication and accurately locate and mark the modified elements.