The invention discloses a method and system for image deformation based on an MRLS-TPS. The method comprises a step S1 of inputting an original image, the weighting parameter alpha and the regularization parameter lambda, selecting a control point set and a target point set corresponding to the control point set from the original image; a step S2 of taking a radial basis function to serve as a TPS kernel, constructing a kernel matrix K of the control point set according to the TPS kernel, constructing a deformation mapping analogue function fp according to a TPS model, and causing the fp to be decomposed into a global affine transformation matrix A and a partial flexure function gp; a step S3 of solving the weight matrix W, the kernel vector Kp and a deformation mapping function fp according to a formula in the step S2; and a step S4 of obtaining a deformed image through backward mapping according to a set {fp(p)} of the deformation mapping function fp. The method has the advantages that (1) deformed images can reserve details well; (2) a deformed function has a simple closed solution; and (3) the method is very high in computational efficiency.