Abstract: The present invention discloses an isogeometric analysis method based on a geometric reconstruction model comprising steps of: dividing boundaries of a CAD model into triangular patches or directly based on point cloud data, generating a closed regular embedded domain, dividing the embedded domain into regular sub-domains, dividing the elements according to a positional relationship between the boundaries of the triangular patches/points and the elements into trimmed elements and untrimmed elements; calculating a minimum directional distance from each vertex of a trimmed element to a triangular patch near the trimmed element; using the minimum directional distance to divide the untrimmed elements into real and virtual elements; using the minimum directional distance as a level set function value, and using a marching tetrahedra algorithm to reconstruct a displayed geometric model based on the regular embedded domain; after obtaining the level set function value, calculating the level set function value of a G