Abstract: We studied relationship between data error rate and network node number or patrol measurement time in traditional wireless network by a series of experiments. The results show that the data error rate increases with node number, and decreases with prolongation of patrol measurement time. In order to guarantee an accuracy rate over 95%, the normal wireless network nodes should be less than 10 and the patrol measurement time should be more than 500ms, which indicates that the traditional wireless network could not satisfy the needs of large scale physical model with hundreds of measurement nodes. An improved wireless network is proposed, that the original single level structure is transformed to the master-slave structure to realize the leveled transmission. The slave network collects the corresponding node's data and conveys to the master network, so the interaction frequency of master network is reduced and the error rate is decreased. By using the new structure, the accuracy of data transmission of 100 nodes can reach 95% or above only by 10 slave networks.