Abstract: In order to solve the overflow of aggregation node in wireless sensor network,a novel connection admission control method (Connection Admission Control based on Wavelet Transform,CACWT) is proposed.In this method,the burst characteristic is reduced by wavelet transform at first,and the border of effective bandwidth and overflow probability are derivation.Then,a simulation with NS2 was conducted to research on the relationship among effective bandwidth,buffer,overflow probability and link capacity.Compared to other tradition algorithms,the result shows CACWT has good suitability.