A method to support dissymmetry service for multicarrier time division duplexing mobile communication system, which contains adopting different uplink and downlink time gap conversion point to support dissymmetry service among multicarrier frequency of different cells and same cell, when the original configured uplink and downlink time gap ratio can not support the service request, then changing the time gap ratio to receiving said request, adjusting service to avoid interference by quick dynamic channel distribution technology, in ending request service, changing time gap ratio in original ratio. Said invention supports different uplink and downlink time gap conversion point, the base station equipment needs establishing isolated uplink and downlink.