When localizing a mobile node in sensor networks, it is possible that a seed node is passed by the mobile node during its sleeping mode, which might lead to failed localization. This paper proposes a dynamic node scheduling scheme P-SWIM based on proactive wakeup and sleep. In P-SWIM, each seed is proactively notified if a mobile node is moving toward it. Hence, only these seeds remain active in full duty when the mobile node passes by them, while the other seeds still stay in sleeping mode. Simulation results indicate that localization algorithms based on P-SWIM can achieve better localization performance than those based on the other two static node scheduling schemes, RIS and GAF. Moreover, P-SWIM incurs least running overhead to the network overall power consumption among the three schemes. In addition, the paper evaluates the effect of node scheduling schemes on localization performance by tuning the parameters of each scheme, which presents guidelines for efficient network deployment for mobile sensor positioning applications.