Abstract: A weighted PIA algorithm based on implicit B-spline curve fitting data points is proposed to make the curve generation faster and the error smaller. First, the offset point set is generated with the data points to be fitted and the given normal vector. Then, the difference vector is constructed through the offset point set to obtain the error control coefficient that needs to be adjusted. In order to make the iteration efficiency higher, the error control coefficient is weighted during the iteration process. Finally, the curve of fitting data points is obtained by using the latest control coefficient matrix. The 5 numerical examples in this paper adopt uniform node sequence, and the experimental results show that, compared with the I-PIA algorithm, the fitting curve error obtained by this algorithm is smaller and the curve can better preserve the characteristics under the same iteration times.