Abstract: Considering that the IEEE 802.15.4 standard slot carrier sense multiple access with collision avoidance (CSMA/CA) mechanism can not provide the data flow of differentiated services, an adaptive parameter adjusting algorithm (DAPA-CSMA/CA) is proposed which is both priority-based and network traffic dynamic. The algorithm is mainly based on the application of real time demand to different nodes assigned different priority levels. The algorithm works to optimize the configuration of the protocol parameters to implement differentiated services and adapt to changes in network traffic by dynamically adjusting the back-off index. On this basis, the channel competition process of the DAPA-CSMA/CA algorithm is analyzed by Markov theory. Simulation results indicate that the DAPA-CSMA/CA mechanism has a strong network adaptive capacity. It can not only reduce collisions between nodes but also reduce packet loss rate, delay, and power consumption, and can better meet the high quality of service (QoS) requirement of the real-time monitoring environment for wireless sensor networks.