To achieve the power-consumption performance of 802.11 DCF, it uses a box-ball model to resolve the packet collisions probability. In consideration of limited retransmissions for each packet, it approximates the state transform of active nodes as a finite-state one-dimension Markovian process. Following these models, the power-consumption performance of 802.11 DCF in a saturated WLAN environment is analyzed based on the concepts of virtual transmission period and average contention window. Results show that packet length and channel rate only has marginal effects on the power-consumption. When nodes are many, the power-consumption performance is mainly affected by the receive power of the node and has little relevance to the transmit power. Simulation results validate the analysis