As wireless transmission technology advances, wireless data centers (WDCs) are more and more widely used as computing infrastructures benefiting from its flexibility and low complexity of cabling. Software-defined networking (SDN) brings new convenience in topology design of wireless data center networks (DCNs) which has a great effect on the performance of data centers. In this paper, we introduce the controllability as a new consideration for wireless data center designers. We defined a new measure for controllability evaluation and compared the existing WDC architectures, uncovered their diversity on properties of dynamics. Then we propose a novel exact topology adjustment strategy to control WDCs more efficiently. Mathematical reasoning and experimental results show the correctness and effectiveness of our method. Our method can not only significantly improve the controllability of existing WDCs, but also applicable in accurate architecture design of wireless network systems.