Crosstalk is the major factor affecting the transmission performance of the VDSL2 system.Most of the existing crosstalk cancellation algorithms are used when the number of the users remains unchanged.In actual access environment

the old users often are offline or the new users are on-line

causing changes of crosstalk environment.In this paper

by using matrix elementary transformations and matrix partition

we propose a novel method to update the Zero-forcing cancellation method as the old users get offline.The new algorithm dramatically reduces the computational complexity of the original Zero-forcing algorithm while maintaining the same performance.Simulation results based on measured data demonstrate the effectiveness of the algorithm.