Abstract: The characteristics of multibar raschel lace were studied in this article,and the spline function was suggested to simulate the loop structure and determine the number and position of control points necessary for forming a loop by a guide bar through weft insertion and fall-plate.And the theoretical model for each type of loop was set up.For solving the problem of distortion of the loop caused by yarn tension,the offset theory and calculation formula were given.This theory assumed that the root of loop was the centre of yarn tension.Applying this model and theory,using(VC++).net to program,the quick,visual and accurate simulation of raschel lace was realized.