Wyner-Ziv Video Coding (WZVC) is considered as one promising video coding scheme for Wireless Video Sensor Networks (WVSNs) due to its high compression efficiency and error resilience functionalities, as well as the low encoding complexity. However, for achieving a good R-D performance, the current WZVC paradigms usually adopt a decoder rate control scheme in which the decoder repeatedly requests the additional data to the encoder for decoding a Wyner-Ziv frame. Therefore, the transmission delay of the additional decoding data is especially long in a multi-hop WVSN. In this paper, based on network coding, we propose a novel rate control method for WZVC. In this rate control scheme, the partial channel codes puncturing task is transferred from the encoder to the relay nodes by using network coding. Then, the decoder can request the additional decoding data from the relays instead of the encoder, and the total waiting time for the decoding data is reduced sequentially. Simulation results validates the proposed rate control scheme.