Recent advances in sensor web geospatial data capture, such as high resolution satellite images as well as corresponding web ready data processing and modeling technologies, have led to the generation of large amounts of datasets on real-time or near realtime observation and measurement. The quality of observation data register has become a 'bottleneck' of sensor web-based applications. In order to improve the quality of sensor data register, Sensor Observation Service (SOS) register middleware is put forward, which includes geospatial sensor observation service (SOS), geospatial catalogue service based on ebRIM, SOS register mediator service, sensor data granule information extraction service, and sensor data granule record generation service. The content and sequence of SOS observation 'synchronous' and 'asynchronous' data register strategy based on service middleware is described. The prototype system is designed and implemented by OGC CSW specification and SWE SOS standard. The EO-1 SOS register is tested, including 2420 WCSLayer observation records in a specified time, and the performance is evaluated. The experimental result shows the efficiency of the 'asynchronous' strategy proposed in this paper is 0.3- 0.4 times fast than that of the 'synchronous'.