The present invention claims a clock synchronization frequency offset estimation method adapted to a WIA-PA network, and belongs to the technical field of industrial wireless sensor networks. The method comprises the following steps: A. receiving a beacon frame, broadcast by a time source device, by a child node in the WIA-PA network in each time synchronization period to obtain a sending timestamp and a receiving timestamp, then adjusting a local time by taking a difference value between the two timestamps as a time adjustment quantity, repeating the process above, and after a plurality of synchronization periods, separately estimating a frequency offset with a statistical signal estimation method; and B. when a node is required to report its own time, compensating a node time with the estimated relative frequency offset With the method, the time synchronization precision is effectively increased, a synchronization error is restrained from freely increasing in the time synchronization period, the synchronization period is prolonged, and both the communication overhead of the network and the energy consumption of the node are reduced.