This paper focuses on a CSMA/CA based consensus problem in which multiple agents are autonomously controlled based on the information received only from the neighbor agents. To boost the control performance, wireless communication technique should be customized considering the features of consensus problem. The aim of this work is to efficiently suppress the interference caused by multiple-access. Different from the conventional communication channel where multiple agents try to access the common destination (access point), individual agents, in the focused consensus problem, try to transmit its own information to as many neighbor agents as possible. To meet above demands, this paper proposes to adaptively change the backoff period considering the number of neighbors' neighbor agents as well as the number of its own neighbor agents. Simulation results show that the proposed CSMA/CA based consensus problem can enhance the convergence performance.