Abstract: This paper presented a new CSMA protocol named double probability detection control for multi-channel random multi-access(DPDMRM).By dividing transmission time of packet into one plus a,using p1 probability detection in time one,and p2 probability detection in time a.Based elaborate control strategy,throughput of the system,throughput of different priority and packet delay are presented by theoretical calculations.Besides,through the wirless sensor networks and computer simulation experiment we proved that thetheoretical analysis is right.Thus,we get the result that DPDMRM is more suitable for WSN.